Part 5

The spermatozoa in the Cockle are oblong and a little curved, and torulated, as it were, whilst they are pear-shaped in _Mytilus_; they are also extremely minute, and their appendages must be very fine, for with a power magnifying 500 diameters they are scarcely to be seen.

In the shell of a _Patella_, _Emarginula_, or _Haliotis_, we have the two conjoined valves of a lamellibranchiate mollusk; and through such forms as _Calyptræa_, _Hipponyx_, _Navicella_, and _Nerita_, we arrive at the ordinary form of the gasteropod with its operculum.

Then follows a disquisition on the progressive tendency to a spiral geometry in these animals, due to a varying plan of conformation, and not to the force of the heart, there being generally an atrophy of the left side of the body. In _Nautilus_ and _Argonauta_, the shell and mantle are reversed in position to what they are in the Gasteropods, whilst _Sepia_ and _Hyalæa_ agree rather with the latter. The symmetrical shell of the lower Gasteropods undergoes a lateral torsion in the higher, spiral forms, to become again symmetrical in the Cephalopoda. The branchiæ in _Patella_ retain a position analogous to that of the same organs in the Lamellibranchiata; in some Chitons they have a tendency to retract towards the anus, as in _Doris_; in _Fissurella_ they waste at the sides and become developed above the neck, as in the spiral Gasteropods; but in them, the right branchia, and right side of the mantle are principally developed. From this torsion arises the form and spire of the shell. In _Aplysia_, where the branchial fissure is far back and to the right side, the right respiratory nerve preserves a superior position, and passes backwards to form its ganglion at the front of the branchial opening; the left, on the contrary, passes under the oesophagus to form a second ganglion, not mentioned by Cuvier, behind the first. In the more spiral Gasteropod the torsion is greater; the right nerve, for instance, mounts upwards over the digestive canal to form its ganglion quite in the left flank, whilst the left goes below the digestive canal to attain the right flank. In _Sepia_ the branchiæ are again symmetrical and abdominal.

The shell of the young _Sepia_ is composed of distant plates, only connected by minute transversely striated laminæ or flattened tubes, producing by their insertion a beautiful appearance of sinuous lines, very like those of a Baculite or Ammonite; and the spongy part of the shell, so constituted, is probably filled with air from the cavity of the body situated immediately in front, the intervening membrane having a peculiar structure. This cavity of the body exists in much lower mollusks; air being apparently secreted in it, to lighten the animal.

The author thinks that, in considering the anatomy and form of the body of the Gasteropoda, about ten species may be taken as types of corresponding families.

1. PATELLA _and its congeners_.--He claims to have been one of the first to show the termination of the oviducts and renal organs between the processes of the branchiæ in the Chitons. As they are commonly phytivorous, the intestine is often very long and disposed in large coils, in double apposition; the buccal apparatus is very remarkable. _Chitonellus_ differs but slightly from _Chiton_, the central elements of its tongue, however, being little developed, though having the same tessellated basement membrane. The tongue of _Emarginula_ differs much from that of _Patella_, having an immense number of serrated side-hooks and a dilated middle portion.

2. CALYPTRÆA, _&c._--The mollusks of this division have often supranuchal branchiæ, as have some of the last; the sexes also are frequently separate, rendering copulation necessary; and they are sometimes partially spiral, with a tendency to form an operculum. However, the little _Ancylus fluviatilis_ appears to be what is commonly called hermaphrodite, with a branchial lamina on the left side, together with the heart and openings of the genital organs; the stomach has a cæcum, and the penis a long filiform appendage; the female parts opening near the rectum and behind the male organs. It must respire by water rather than by air, for, in a rapid stream, the stones at the bottom are covered with _Ancyli_ (upon which also its round oothecæ, each containing four or five ova, are deposited), and it appears impossible for them to get to the surface to breathe. On the contrary, the lake-_Ancylus_, though the margin of its mantle is ciliated, may perhaps come to the surface, ascending the stalks of the Water Persicaria, on which it is mostly found, and on which its oothecæ are deposited. When the dark cuticle of this last minute creature is removed, its organs may be seen to be reversely disposed to those of the larger species, the heart being placed to the right, before the apex of the shell, and the rectum also on the same side.

3. DORIS, _&c._--The little _Doris aspera_ swims, back downwards, on the surface of a glass of sea-water, copulates, and deposits its semicircular oothecæ. The brain of the common Lemon Doris is of a fine orange colour, enveloped in a glandular matter, and is constituted by a complicated assemblage of ganglia: there are acoustic sacs and dark ocular spots upon it. There are six ganglia on the buccal mass, and about six or eight minute ones on the stomach. The anal sac appears to be a purple- or ink-bag; and the so-called matrix is composed of a peculiar substance, swelling enormously in water, of which it renders a large quantity viscid, and being also coagulable by alcohol and bichloride of mercury, but not by heat. Spermatozoa were found in the genital vesicle, as well as in the epididymis and its cæcum. The spines of the lingual plate are uniform, and in number about 10,000.

4. APLYSIA, _&c._--_Aplysia_ has been before alluded to. Cuvier, in his generally beautiful drawings, has scarcely done justice to (5) _Ianthina_, nor to its beautiful float and ootheca; it is peculiar for its fins, and the disk at the back of the foot. With respect to _Magilus_, it should be removed from the (6) Tubulibranchiata, its animal being a _Purpura_ in structure, with a bent horny operculum, and a very long linear appendage on the right side of the head, leading to the supposition that the animals are of different sexes, though there seem to be difficulties in the way of sexual congress. In the specimen examined, the spire of the shell was not solidified; the animal had a short proboscis, with rather bent subulate feelers, and eyes on the outside; it had also a rich purple secretion near the rectum on the right side.

7. TROCHUS, _&c._--Some of the species of _Trochus_ surpass even _Emarginula_ in the beauty of their lingual apparatus. The renal organ opens into the bottom of the branchial cavity, contrary to its disposition in _Helix_ and _Lymnæus_, where its exit is near the respiratory orifice. In _Planorbis_, that part of the respiratory cavity receiving the excretions seems separated by an imperfect valve from the right portion. With respect to the secretion of this organ, it consists, in both Gasteropoda and Lamellibranchiata, of numerous pellucid globular bodies, containing opaque earthy nuclei or granules, and presenting different appearances in _Anodon_ (for instance), _Cyclostoma_, _Buccinum_, and _Helix_. When these bodies are incinerated, lime is left, which in some cases appears to have been combined with oxalic acid. The little _Nerita litoralis_ presents the structure of the Turbonidæ very prettily and in small compass, particularly in the very long spiral tongue. _Delphinula_ has the fringed mantle and sides and very wonderfully armed tongue of the other Trochidæ. _Melania_ is of similar organization to our well-known _Paludina_, the stomach compound, the mantle and bilobed head fringed, and the latter marbled like that of _Paludina_. _Ampullaria_ appears to be truly amphibious.

8. BUCCINUM, _&c._--_Natica_ presents much the same structure as the common _Buccinum_, but has a muscular disk anterior to the mouth,--a disposition, with some variations however, found in other mollusks. The first and second stomachs are at a distance from each other, the tongue is little developed, and the branchiæ (often single in the Turbonidæ) two in number. _Purpura_ also differs but little from _Buccinum_. _Ovula_ is a less attainable mollusk: the foot is long and rather narrow, and subventral rather than subtrachelian, with a sinuosity on the right of the neck, where also is a short hooked penis in the male, receiving a vas deferens from near the rectum behind; there is a large and small branchia, and the reflected portion of the mantle is covered with tubercles and tentacles,--no doubt a fine garnish in the living animal; the mouth has a muzzle, and there are small eyes on the external sides of the curved, awl-shaped tentacles; the elements of the tongue are beautifully toothed and serrated.

9. LYMNÆUS, _&c._--Of the air-breathing aquatic and (10) terrestrial gasteropods the most interesting particulars are their generative organs, which the author proposes to re-examine. The brain of _Helix aspersa_ is composed internally of pyriform or oval ganglionic vesicles, each giving origin to one or more nervous fibres. The acoustic sacs are similar to those of _Doris_. The nerves from the upper part of the ring are enveloped in a darkish neurilema, and comprehend no doubt olfactory, optic, and tactile twigs; there being the buccal ganglia for taste, and the acoustic sacs for hearing; the twigs, however, forming the buccal or pharyngeal ganglia have a broad double root on each side, near the origin of the above three nerves. The lower part of the brain is very analogous to that of _Sepia_, giving off nerves to the foot, and external and internal respiratory ones to the mantle, respiratory opening, branchiæ, &c. _Lymnæus_ has the cephalic ring formed by about twelve ganglia, exclusive of two large and two minute ones on the buccal mass. The upper portion of the ring has ganglionic swellings, but in other respects the nerves are as in _Helix_. Its lower portion consists of two pedal nerves, and has the acoustic spot and a minute ganglion upon it; behind, this lower portion consists of five ganglia connected with both the anterior and upper swellings by a cord, but separated from the former by the aorta, as usual, and giving nerves to the flanks, pulmonary orifices and sac, heart, stomach, and viscera. The lower ganglia are bright yellow.

With respect to the Pteropoda, the branchiæ in _Hyalæa_ exist as a delicate membrane under the swollen part of the shell, in structure much like the same part in the Ascidians, the inlet being through the anterior opening of the mantle. There are eyes at the fold of the mantle behind, and two small tentacles above the mouth; the heart and rectum being on the left side, and the generative opening at the base of the right ala. _Cleodora_ is a very beautiful creature, with the same disposition and structure of viscera; brain-spots but no eyes were visible; the mantle had beautiful muscular bands; the branchiæ as above; the buccal apparatus is imperfect in both. _Cleodora_ has similar membranous expansions with _Hyalæa_, and also a sort of triangular lip.

_Argonauta_ has a lachrymal pore before and beneath the eye. The beautiful and obvious respiratory mechanism in the Cephalopoda needs not to be described. There is a large sac behind the viscera of the Argonaut, which opens on each side; it is perhaps of some hydrostatic use. There are at least three pairs of salivary glands, of which four open on the floor of the mouth, and two or three at the commencement of the gullet. Several small shells of Pteropoda and fragments of Cephalopods were found in the stomach, on which was observed the large nervous ganglion found in all these, as well as in lower mollusks. The branchial nerves have each two ganglia, of which the last at the root of the branchiæ is rounder than the other; the branchial hearts have processes as in _Sepia_. In _Sepia_ two openings lead from the respiratory sac into the cavity containing the venæ cavæ and their secreting appendages often imbued with glittering crystalline particles, and from the above cavities a wider opening on each side leads into a second sac further back, situated in front of the shell. There are auditory sacs in the Argonaut. The oviducts have separate openings, but originate together. Both _Sepia_ and _Argonauta_ are infested with a subcutaneous filiform entozoon, hooked anteriorly and rolled up spirally in the former. _Loligo media_ and _Sepiola_ have but one oviduct, and the two large, glandular, laminated organs, opening at their summits, are wanting in _Argonauta_ and _Octopus_. In _Sepiola_ one would almost think that copulation takes place, for the author has taken what he supposes to be the capsules of Needham, with dilated oval ends, tubular and bent pedicles or processes, enclosed elastic filaments, and adhering zoosperms, from the oviducts of the female: he has made the same observation also in _Sepia_. The latter has very similar male organs to _Octopus_, as described by Cuvier. In the embryo _Sepia_, the yelk enters below the mouth and opens into the upper stomach, but the beak of the animal also appears to be inserted into it behind. The vitellus in reality therefore enters by the foot, as it does in _Bulimus_, and probably in all Bivalves.

* * * * *

On the Linnean Manuscript of the 'Museum Ulricæ.'

By SYLVANUS HANLEY, Esq., F.L.S.

[Read Dec. 3, 1858.]

Not the least important result of the investigations of the Committee appointed by the Linnean Society to examine the condition of the collections and manuscripts of Linnæus, was the rediscovery of a written copy of the 'Museum Ulricæ.' The volume was manifestly, from internal evidence, a legible transcript of the original manuscript of that work, with alterations and interpolations in the peculiar handwriting of the author. It was, indubitably, the unpublished catalogue so often mentioned in the tenth edition of the 'Systema,' and contains descriptions of certain species alluded to as defined, yet, strangely enough, omitted in the printed edition. It is worthy of notice for many reasons: it corrects the frequent misprints; explains the many fallacious allusions to preceding species, their sequence being very different; it exhibits those early synonyms, which, culled from comparison with the actually described specimens, had been eventually supplanted by supposed better representations; above all, it imparts to us those original headings, or diagnoses (condensed from the subsequent details), which had been suppressed, of old, in favour of those already published in the 'Systema.'

This wholesale substitution, adopted by Linnæus, as a ready method of avoiding a tedious revision of all the headings, when he absorbed in the more comprehensive groups of his 'Systema' the members of manuscript genera he had determined to reject, involved a serious amount of confusion; for, oftentimes, the species of the two works, although designated by the same appellations, were totally distinct; and the combination of the diagnosis of the one with the details of the other displayed an array of features not known to be associated in any object in nature.

The generic arrangement exhibited in the manuscript differs essentially from that which appeared in the final edition of his 'Systema Naturæ.' As a whole, it is decidedly inferior, yet it segregates certain natural groups, such as _Lyra_ and _Cassida_, the value of which have been acknowledged by all modern naturalists. The following list and sequence of the genera comprised in it, cannot, indeed, be regarded as an entire system, for certain groups, viz., _Chiton_, _Lepas_, _Teredo_, _Sabella_, and the typical forms of _Mya_, _Mactra_, and _Anomia_, were not at that period represented in the Museum; but it is not devoid of interest, since it manifests a transitional stage in the progressive advance to that matured scheme which was finally elaborated in the pages of his revised 'Systema.'

Dentalium. Patella. Nerita. Helix. Turbo. Trochus. Turricula. Buccinum. Lyra. Morion. Conus. Voluta. Strombus (not that of the 'Systema'). Harpago (=Strombus). Murex. Cassida. Cypræa. Bulla. Haliotis. Nautilus. Cymbium (=Argonauta). Spondylus. Ostrea. Pecten. Arca. Pinna. Mytilus. Solen. Tellina. Chama (not that of the 'Systema'). Cunnus (=Venus). Pholas (not that of the 'Systema'). Trunculus (=Donax). Bucardium (=Cardium).

Besides the four genera (_Chiton_, _Lepas_, _Teredo_, _Sabella_) that were excluded from this catalogue, either from the absence of specimens, or from mistrust of their being veritable Testacea, six of the remaining 32, namely, _Pholas_, _Mya_, _Mactra_, _Chama_, _Anomia_, and _Serpula_, were likewise omitted, not being yet eliminated from _Solen_, _Bucardium_, _Spondylus_, _Ostrea_, and _Dentalium_. To counterbalance these, we find no less than eight subsequently abandoned groupings:

_Turricula_ (an undefined amalgam of the long-spired species of _Buccinum_, _Murex_, and _Strombus_).

_Lyra_ (the _Harpa_ and _Purpura_ of the Lamarckian school).

_Morion_ (an unnatural compound of _Eburna_, _Auricula_ proper, _Pythia_, _&c._).

_Strombus_ (a combination of the immature members of the received genus with _Pyrula_, _Fasciolaria_, and other allied forms).

_Cassida_ (nearly the modern _Cassis_).

_Pecten_ (equal to _Lima_ and _Pecten_).

_Chama_ (the _Tapes_ of recent conchologists).

_Pholas_ (chiefly composed of _Artemis_ and _Lucina_).

It may be remarked, moreover, that the simple univalves commence, and the bivalves close the series; the exact converse of the order in which they are marshalled in the two principal editions of the 'Systema Naturæ.'

I feel assured, after a careful study of the manuscript, that the names eventually allotted to the shells of the 'Museum' did not result from a careful comparison of the royal specimens with the typical examples in the private collection of our author, but were attached to the species, either from the identity of the written and printed synonymy, or from the general accordance of their described features with the meagre characteristics enumerated in the prior publication.

The erased nomenclature of the species, however, was very dissimilar, and was scrupulously based upon a supposed identity of the specimens with those delineated by Rumphius, Klein, and d'Argenville. Assuredly at that period of his career, our author entertained the same profound respect for the laws of priority which is professed by all modern naturalists; and I hesitate not to affirm that, from the crude and inharmonious theories of his predecessors, he eliminated a system of Conchology that was better suited to the requirements of the age he lived in than any more elaborate arrangement would have been. For simplicity attracts the student, whom a more complex (even if more natural) method would repel; and for the collection of an adequate mass of materials wherewith, eventually, to build up a more symmetrical and widely-based structure, a multitude of comparatively unskilled labourers is more efficacious than a small knot of the most erudite architects.

Before inviting the attention of my readers to the original headings of the 'Museum Ulricæ,' and to my brief account of the variations in the written copy from the text of the printed version, I must premise, that it has not been my practice invariably to notice, in the summary, such trifling differences of construction as the preferential use of the ablative for the nominative case, where the verbal change involved no alteration of the precise meaning.

MUSEUM LUDOVICÆ ULRICÆ REGINÆ.

CONCHYLIA.

CHITON, LEPAS.

Nothing relating to these two genera was found in the copy.

PHOLAS.

The _Pholas_ of the manuscript is perfectly dissimilar to that of the 'Systema.' Our author had evidently, when he first wrote the 'Museum Ulricæ,' not appreciated the remarkably striking characteristics of this group, having located the only species he then knew (for _P. candidus_ seems a subsequent discovery) with the _Solens_.

P. CANDIDUS. Not mentioned in the manuscript.

P. CRISPATUS. _Sol._ ovatus, obtusissimus, cardinis dente depresso rotundato.

The Appendix to Lister was not cited; "Habitat in Anglia, Suecia," was appended to the description, which in many respects was inferior to the published one. The account of the hinge was merely "Cardo dente dilatato rotundato extus excavato."

MYA.

The three incongruous forms assorted as _Myæ_ were not so united in the MS.; the second being very properly placed with the _Mussels_, the other two ascribed to _Solen_.

M. LUTRARIA. _Sol._ ovali-oblongus, cardine laterali dilatato semiorbiculato.

In lieu of the reference to Lister (whose work does not appear to have been consulted by our author at the period when this portion of his manuscript was written), plate 45, figure N, of Rumphius was quoted as illustrative. The published account of the hinge is much more complete than the written one, which was apparently drawn up from a worn specimen; it ran as follows: "Cardo extus vix gibbus, intus constans laminis 2 semiorbiculatis concavis introrsum spectantibus."

By a slip of the pen, in my "Ipsa Linnæi Conchylia," I had termed Brown's figure of the Linnean _Mya lutraria_, _L. oblonga_, instead of _L. elliptica_.

M. PERNA. _Myt._ lævis, cardine terminali unidentato.

The intended name was _M. Magellanicus_.

M. VULSELLA. _Sol._ oblongus, linguæformis, cardine terminali dilatato semiorbiculato.

"Pinna linguaformis subfalcata" was written after the reference to the 'Museum Tessinianum;' hence it seems that Linnæus did not himself consider that he had used the binomial method in that work, or he would have quoted it as _P. lingulata_.

"Rumph. 148. t. 46. f. A," and "Gualt. t. 90. f. H," were the unpublished synonyms.

SOLEN.

Testa valvulis utrinque hiantibus. Cardo dente unico inflexo recurvo.

The _Mya lutraria_, _M. vulsella_, and _Pholas crispatus_ were originally included in this genus.

S. VAGINA. _S._ linearis rectus, cardinibus unidentatis.

"Habitat in Indiæ littoribus arenosis: in mari Rubro (_Hasselquist_)" was the recorded locality in the MS., where the European shell delineated by Gualtieri was not then included: "Klein, 163. t. 11. f. 65" (a copy from the cited figure of Rumphius) was its substitute.

S. SILIQUA. _S._ linearis rectus, cardine altero bidentato.

The wretched drawings of Argenville were not quoted; but "Bonan. 2. f. 56" (error for 57), "Plane. t. 3. f. 6," and "List. Ang. 192. t. 5. f. 37," were cited instead.

S. ENSIS. _S._ linearis subarcuatus, cardine altero bidentato.

The final remark was not in the MS.

S. CULTELLUS. _S._ ovali-oblongus curvatus.

"Habitat in Amboinæ littoribus arenosis" is an addition of the MS. The intended name (derived from Rumphius) was _cultriformis_.

S. RADIATUS. _S._ ovalis, cardinis costa tereti.

"Habitat in littoribus arenosis Xulii(?) Amboinæ" is an addition to the published account. The intended specific name was _violaceus_, an appellation bestowed upon it by Rumphius: "_solida_" was an emendation.

S. STRIGILATUS. _S._ ovalis, oblique striatus.

"Bonan. 2. f. 76" (error for 77) was an unpublished synonym.

S. ANATINUS. _S._ ovatus membranaceus, costa falcata.

_Rostrum anatis_ was the intended name.

TELLINA.

Testa altero latere inflexa. Cardo dentibus aliquot, raro lateralibus.

T. GARGADIA. _T._ antice rugosa, rima dentata.

The absurd "marginis posticum latus remotum" was a misprint for (dens) "marginis posticus, latus, remotus."

T. LINGUA-FELIS. _T._ subovata scabra.