Part 12

Ornithocheirus Cuvieri (Bowerbank).

Case. Comp. Tablet. Specimen. =J= _c_ 15 1-3

A portion of a premaxillary bone fractured at both ends, and two inches long, corresponds with Dr Bowerbank's fossil figured Pl. XXVII. fig. 1, 3, 4, in the Palæontographical volume for 1851. The palate is just as wide; the median ridge, the same; the teeth the same in shape and as far apart. The jaw is of the same depth, but does not deepen so rapidly behind. The only other difference is that the sockets of the teeth are less prominent on the sides, and appear to look more directly down.

The ridge in which the converging sides meet is well rounded in a dentary bone which may have pertained to this species. In the space of two inches and a quarter are 5 teeth, the posterior four extending over two inches, the other pair being in front. The palatal surface is 3/4 of an inch broad behind the third tooth, and rather more than 5/8 of an inch broad behind the fourth tooth. The length of the 4th or of the 5th sockets is two-thirds that of the second or third. In front of the 5th tooth, the jaw is an inch deep, and it tapers in a curve to the anterior end. The teeth behind the third have interspaces greater than the length of the sockets; that between the 4th and 5th being 3/8 of an inch, while the socket only measures a quarter of an inch long. Behind the 2nd socket commences the palatal groove, broad in fronts but narrowing behind; and its sides instead of diverging as in the type, are concave so as to form a channel like a straightened _Siliquaria_ shell. The halves of the palate bevel off so as to make a right angle with each other, and greater angles with the flat sides.

III.

Ornithocheirus machærorhynchus (Seeley).

Case. Comp. Tablet. Specimen. =J= _c6_ 35 1

Dentary bone. Broken at both ends, and wanting all its teeth, this interesting fossil shows the suture where its whole length rests on the angular bone which almost reached to the termination of the beak, quite unlike what is seen in any German Pterodactyle.

It is a narrow mandible, less than three quarters of an inch wide, with the alveolar margins parallel. The palatal surface 1-1/2 inch long, is divided into 3 equal strips; the middle one being a deep glossal groove, slightly narrowing in front, and deepening behind, made by two inclined flat surfaces. The lateral strips are horizontal behind, and in front slope a little outward. The tooth-sockets are oval, directed outward, and as long as the interspaces, though these seem to get longer behind. In an inch and a quarter there are four teeth. Below the teeth, the sides of the jaw are compressed: though nearly parallel at the hinder fracture, the flattened surfaces approximate in front till they meet in a sharp keel, which appears to make an acute angle of about 45° with the palate; and below, where the jaw is an inch deep extends for half an inch in front of the suture with the angular bone: this suture is straight and irregularly concave, and in an inch and a quarter approximates to within 5/8ths of an inch of the palate.

IV.

Ornithocheirus tenuirostris (Seeley).

Case. Comp. Tablet. Specimen. =J= _c2_ 12 1

Middle part of a premaxillary bone fractured behind and in front, slightly distorted by compression; it is 2-1/8th inches long, and nearly resembles _O. compressirostris_ (Owen). The palate is about 1/2 an inch wide in front, and 5/8ths of an inch wide behind; it is compressed mesially into a strong angular keel, between which and the teeth there is a shallow groove on each side. The groove dies away behind, and the converging parts of the keel occupy the whole space between the teeth. The teeth-sockets are small, elliptical, not opposite to each other, and placed along a distinct flattened tooth area, which looks downward and outward and separates the palate from the side of the jaw. The first pair of sockets preserved are almost 3/16ths of an inch long and 1/16th of an inch wide. The interspace between that tooth and the next tooth behind is 7/16 of an inch. Separated by similar interspaces, behind these on one side are two sockets, and on the other side one socket. The sides are flattened in front, and convex behind, (making the section of the jaw lanceolate); they are compressed and round into a narrow rostral keel. The height from the palatal ridge to the rostral keel in front is 11/16ths of an inch; behind it is fractured, but the height was probably 14/16ths of an inch.

The palatal keel, distance of the teeth, and proportions of the jaw, distinguish it from O. compressirostris (Owen).

V.

Ornithocheirus Oweni (Seeley).

Case. Comp. Tablet. =J= _c_ 20

The small piece of premaxillary on which this species is founded indicates a small animal, and nearly resembles the jaw of _O. microdon_.

It is scarcely an inch long; nearly 9/16ths inch high behind, and nearly 7/16ths of an inch high in front, so that it tapers very rapidly, and could scarcely have been an inch longer in front.

The nose is well rounded, but the sides are a little concave, and become well pinched in in the middle, behind, showing the near approach as I think to the nostril.

The palate half an inch broad, is divided into two concave channels by the strong and sharp median ridge, which projects below the alveolar margins. The dental margins are not rounded as in _C. microdon_, but flattened, making more than a right angle with both the outer side-wall and palate. The interspaces between the teeth are rough, looking as though they had supported minute teeth. The alveolar margin is a tenth of an inch wide; along it are the perfectly circular sockets, a sixteenth of an inch in diameter. There are 3 sockets between 5/8 of an inch, so that they are separated by 3 times their diameter. The palate is obliquely impressed with blood-vessels running forward to the teeth from the median ridge.

The points in which this jaw differs from that of _O. microdon_ are that in this species the teeth are circular instead of being oval; that the interspaces here are as long as in that species, though this jaw is only two-thirds the width; that instead of having a sharp keel on the upper surface, this has a well rounded roof. That though the jaw is scarcely higher than it is wide, it shows strong furrows running up to the nares, while in _O. microdon_, though the proportions are the same, the sides are perfectly flat without trace of pinching in, while the line of the nasal opening is indicated by a faint furrow running all along the jaw. And lastly it differs in size, which, where the sutures are lost, may be important in discriminating forms.

VI.

Ornithocheirus microdon (Seeley).

Case. Comp. Tablet. Specimen. =J= _c_ 29 1-2

Premaxillary bone. The fossil is nearly 1-3/4ths inch long, and at the proximal end, where it is less than 3/4ths of an inch high, has flat sides, which converge to form a keel which is depressed anteriorly and rounded so that where fractured in front the bone is 7/16ths of an inch deep. The palatal surface contains two wide concave channels, between which descends a sharp median ridge, which behind becomes more prominent than the alveolar border.

The palate is 5/8ths of an inch wide. The alveolar margins are compressed and rounded. The small tooth-sockets are oval, and four are contained in 1-1/8th inch; they look downward.

There is a small tip of a jaw associated with this fossil, which is so like that it might be part of the bone broken off before fossilization. It corresponds in every way except that the teeth are closer. In this terminal lanceolate fragment there are in 5/8ths of an inch four teeth. The snout is terminated by two, which are close together.

VII.

Ornithocheirus Huxleyi (Seeley).

The only specimen of this species yet known is the greater part of a dentary bone contained in the Museum of the Geological Survey. An inch and 1/4 long and 3/4ths of an inch wide, it is less than half an inch deep: the sides slowly converge towards the front, and it appears to have had an obtusely lanceolate beak. The under surface is convex, too inflated for trace of a keel, and tapers to the end of the beak, which, with the left alveolar margin is abraded. The palatal surface is smooth at its front end, but two diverging ridges soon arise and form the boundary of a posteriorly deepening mesial channel, which is a quarter of an inch wide at the fracture. These ridges too, which are parallel with the compressed and rounded alveolar margins, convert the lateral spaces into shallow channels. The right side shows the sockets of 3 small oval teeth separated by interspaces wider than teeth. A tooth and two interspaces measure 7/16ths of an inch.

The only cretaceous Pterodactyle which this at all resembles is _O. microdon_, but the palate is wider than in that species; the sides converge towards each other more rapidly, as though it belonged to a species with a shorter snout.

I am indebted to Prof. Huxley for the opportunity of making a notice of this species.

VIII.

Ornithocheirus oxyrhinus (Seeley).

Case. Comp. Tablet. Specimen. =J= _c2_ 13 1

This well-marked species is a portion of a premaxillary bone 1-1/4 inch long, fractured behind and in front. The palate is half an inch wide; its two halves are inclined to each other at a considerable angle, and where they meet form a more prominent keel. The tooth-sockets look more outward than downward, are nearly circular, separated by interspaces as long as the sockets; three sockets and two interspaces measure one inch. The jaw is about 5/8ths of an inch high in front, and about 1/16th of an inch higher behind. The sides are flat and converge like the sides of a wedge to a sharp rostral keel.

IX.

Ornithocheirus xyphorhynchus (Seeley).

I have seen but one example of this form. It has lost much of the outer layer of bone, and shows on the sides impressions like tooth-marks from an eater of Pterodactyles. A groove which has some appearance of being due to fracture traverses each side, but the specimen is symmetrical, and has its characters in no way changed by the accident.

It is a portion of a lower jaw of a long-beaked Pterodactyle of the _O. Sedgwicki_ type, with parallel sides, and the rounded basal ridge nearly parallel with the palate.

The fragment is two inches long, showing four large and obliquely set sockets in If inch. The tooth-sockets are on the outer two-thirds of the palate, and looked forward, upward, and outward The interspaces each measure 5/16ths of an inch.

Each half of the palatal surface which is 5/16 of an inch wide, inclines to the other half at a right angle, being parted by a narrow groove; the diameter of the jaw is half an inch.

The depth of the jaw is 5/8ths of an inch in front, and 3/4ths of an inch behind. The sides are flat and approximate below to a sharp keel. This species is one of many in the collection of W. Reed, Esq. of York, kindly placed in my hands for the elucidation of those in the Woodwardian Museum.

X.

Ornithocheirus Fittoni (Owen).

Case. Comp. Tablet. Specimen. =J= _c_ 14 1, 2

The fragment is 1-1/2 inch long, with two large elliptical tooth-sockets on each side of the flattened palate, and one pair in front. The third socket is separated from the fourth by a considerable interspace. Between the third sockets arises the median palatal ridge, and from the inner margin of each socket a lateral ridge appears to be continued. Behind the third socket the jaw measures 11/16ths of an inch from side to side, and 10/16ths of an inch high. The sides converge and round convexly into each other. The jaws appear to have been long; It is only known by upper jaws. The type specimen shows the socket of another tooth in front of the last one figured by Prof. Owen. It is directed outward at a greater angle, and separated from the hinder one by a wall not 1/16th of an inch thick, and the teeth of this pair must have been parted from each other by a film equally thin. There is no truncation of the snout as in _O. Woodwardi_.

Another specimen shows some variations. This fragment of a premaxillary bone is fractured through the third pair of tooth-sockets in front and through the seventh pair behind. It is about 2-1/8th inches long; the palate is 11/16ths of an inch wide behind the great tooth, and maintains the same width. The jaw is 11/16ths of an inch high behind, and 10/16ths high in front. The sides are gently convex, and imperceptibly unite to form the well-rounded depressed mesial ridge of the beak. From the front of the third to the back of the fifth socket measures 1-3/8ths inch. The sockets are ovate, rather smaller, and closer together than in the type of _O. Fittoni_; margins elevated. The variations from types are so many, and often so considerable, as to suggest the idea that the fossil groups called species may in the living animals have often been genera.

In all the specimens the end of the palate is a little reflected upward.

XI.

_Ornithocheirus dentatus_ (Seeley).

Case. Comp. Series. Specimen. =J= _c1_ 9 1

A fragment of premaxillary bone two inches long, fractured behind the socket for the seventh tooth. It most nearly resembles _O. Sedgwicki_ and _O. Cuvieri_. Behind the second tooth the palate is 1/2 an inch wide; behind the sixth socket it is 5/8ths of an inch wide; the distance between these points is nearly 1-1/2 inch. The palate is flattened, with a sharp slight mesial keel and a wide concave channel on each side which dies away in front. The first pair of teeth are in front of the snout, rather small, and look forward. In this specimen the large third tooth is not developed on the left side. The second and third sockets are large and close together; the succeeding teeth are parted from each other by interspaces equal to their own diameter. They are gibbously elliptical. The sides of the jaw are gently convex from above downward; they round into each other to form a narrow rostral keel. Behind the second socket the jaw is 1/2 an inch high; behind the sixth it is nearly 7/8ths of an inch high.

The grooved and relatively wider palate, and the relatively smaller teeth, abundantly distinguish this species from _O. Sedgwicki_ (Owen).

The smaller, more circular teeth, placed closer together, distinguish it from _O. Cuvieri_ (Bowerbank).

XII.

Ornithocheirus scaphorynchus (Seeley).

Case. Comp. Tablet. =J= _c_ 22

This fragment of premaxillary bone is 1-1/2 inch long. The palate is 1/2 an inch wide behind, and the jaw is rather more than 1/2 an inch high; behind the second tooth it is nearly 5/8ths of an inch high. The sides converge superiorly to form a well-rounded keel. The palate is flattened, with a slightly elevated blunt median keel. There appears to be a pair of small teeth in front of the snout as usual, and six on the palate, with an indication of another at the posterior fracture. The teeth are of moderate size and almost circular. In the form of the bone it is readily distinguished from all the species enumerated.

XIII.

Ornithocheirus platystomus (Seeley).

Case. Comp. Series. Specimen. =J= _c6_ 32 1

An ill-preserved fragment fractured in front and behind, yet indicating a distinct species. The palate is flat, with the faintest median ridge, and the sides are flat and round into a narrow rostral keel, which in front approximates rapidly towards the palate. The first pair of sockets are missing; what appears to be the second pair are about 1/8th of an inch long, separated from the pair behind by an interspace of 1/4th of an inch. These are ovate and less than 1/4th of an inch long, and separated from the next pair by an interspace of not less than 1/4th of an inch. The height of the jaw over the first pair of sockets preserved is 9/16ths of an inch; over the second pair it is 14/16ths of an inch; the space between these points is 9/16ths of an inch. Behind the second pair of teeth the palate is nearly 5/8ths of an inch wide.

The only species which it resembles is _O. brachyrhinus_, but differs from that in the flatter, narrower palate, which makes a greater angle with the rostral keel, and in the smaller teeth, which are separated by wider interspaces.

XIV.

Ornithocheirus nasutus (Seeley).

Case. Comp. Series. Specimen. =J= _c2_ 11 1

A fragment of a premaxillary bone 6 inches long. It somewhat resembles _O. Cuvieri_ in the aspect of the palate, but the jaw is more elongated, and expands from side to side at the anterior end. The teeth are opposite to each other in front, but become irregular after the sixth. The palate measures behind the second pair of sockets 3/4ths of an inch, behind the third pair it is a sixteenth of an inch wider, behind the ninth pair half an inch, and in the last two inches it begins to widen again. A sharp keel arises behind the second pair of sockets and becomes more prominent to behind the tenth pair, when the channel which accompanies it on each side seems to disappear. The first pair of teeth, which look forward, is smaller than the second and third pairs; they are closer together than those which follow. The third sockets are 7/8ths of an inch from the tip of the snout. Then follow three smaller, more circular teeth, which are separated from each other by interspaces as long as the sockets. The back of the sixth sockets are 2-1/4 inches from the tip of the snout. Then follow two larger more elliptical sockets; after which the sockets become smaller and are separated by longer distances, that between the 10th and 11th pairs is nearly 3/4ths of an inch.

The height of the jaw behind the second pair of sockets is 5/8ths of an inch, behind the sixth sockets 15/16ths, behind the tenth sockets 1-1/4 inch. In front, the nose has the aspect of being compressed from above downward, and behind it is compressed from side to side. The sides are flattened and round into a narrow rostral ridge which is depressed at the anterior end.

XV.

Ornithocheirus polyodon (Seeley),

Case. Comp. Tablet. =J= _c_ 21

This species is founded on the anterior end of a premaxillary bone; in form not unlike _O. Fittoni_. It is 5/8ths of an inch wide; the lateral margins approximate very slowly, and in front it appears to be truncated. It is an inch and a quarter long, and in that space were on each side six large round teeth, almost as close together as they could be, five on the palate and a pair in front. The terminal two are no wider apart than the rest, and point more forward. A moderate, sharp, median ridge descends in the flattened palate, making its lateral halves a little concave. The front termination of the palate is slightly reflected upward. The jaw, which is 1/2 an inch deep behind, tapers to its termination more rapidly than does _O. Fittoni_. The flat sides similarly converge, and form a well-rounded ridge, which does not get blunter in front. From their close approximation, it results that the tooth-sockets are entirely above the palatal surface, so that they are better seen from the side of the jaw than from the palate.

It is a clearly marked species, as well distinguished from _O. Fittoni_ by the closeness of its teeth, as _O. Sedgwicki_ is from _O. Cuvieri_.

XVI.

Ornithocheirus denticulatus (Seeley).

Case. Comp. Series. Tablet. =J= _c5_ 28 1

This is a species which can only be confounded with O. polyodon. It is a fragment of premaxillary bone 1-3/4 inch long, fractured through the seventh socket. It differs from O. polyodon in having larger teeth, which are wider apart, look more downward, have a narrower palatal interspace between each pair, and a rostral keel, which is more compressed from side to side behind and from above downward in front, and makes a greater angle with the palate.

The sockets are more uniform in size and closer together than usual, the second and third pairs being but slightly larger than the others; all are broadly elliptical. The palatal keel becomes sharp and prominent behind the fourth sockets. Behind the second pair of sockets the height of the jaw is nearly 7/16ths of an inch, behind the fourth sockets the height is 10/16ths of an inch; the distance between these points is about 10/16ths of an inch.

XVII.

Ornithocheirus crassidens (Seeley).

Case. Comp. Series. Tablet. =J= _c1_ 2 2

This is a fragment of a ?premaxillary bone, fractured behind through the socket for the fourth tooth. It approximates to O. colorhinus, but differs chiefly in the nose not extending in front of the first pair of teeth; in there not being any lunate area above the first pair of teeth; in there being but one tooth in front, which is relatively large; in the socket for the fourth tooth being quite close to that for the third tooth, and in the palatal sockets looking much more outward. The nose also appears to be better rounded.

The fragment is 1-7/8 inch long. The second and third sockets, with their interspace, measure 1-1/8 inch. On the opposite side the first socket is intermediate in position between the first and second.

Though not likely, it is just possible that this might be the premaxillary bone of O. eurygnathus.

XVIII.

Ornithocheirus brachyrhinus (Seeley).

Case. Comp. Tablet. =J= _c_ 24

This fragment of a premaxillaiy bone is fractured behind the sockets for the third pair of teeth. It is 1-1/8 inch long, and shows one pair of small teeth in front and two pairs of large ovate teeth on the palate. The first pair are divided from each other and from the second pair by films of bone; and the second pair are separated from the third by rather more than half the length, of the third socket. Behind the third pair of sockets the palate is 5/8ths of an inch wide; it is flattened, and has a blunt moderately elevated mesial ridge. Behind the second pair of sockets the jaw is 5/8ths of an inch high; behind the third pair of sockets it is 3/4ths of an inch high; the distance between the places of measurement is 1/2 an inch. The sides are flat and converge to a rounded nose. The jaw is rounded from side to side in front, and the outline of the top of the nose rounds over the blunt termination of the snout above the teeth on to the palate.

In the shortness of the nose it somewhat resembles the _?P. giganteus_ (Bowerbank), but the jaw attenuates less rapidly, is truncated, and has larger teeth.

XIX.

Ornithocheirus enchorhynchus (Seeley).

Case. Comp. Tablet. =J= _c_ 25

This species nearly resembles _O. brachyrhinus,_ from which it differs in larger size, with a relatively wider palate, which is without a keel, and in a larger front pair of teeth. It approximates towards _O, colorhinus_, but is smaller, and wants the rugose lunate area over the front pair of teeth characteristic of that species. There are many varieties or species nearly related to this type, but from their imperfect preservation and the small part of the head which they represent, it is not possible to give descriptions of them.

XX.

Ornithocheirus eurygnathus (Seeley).

Case. Comp. Series. Tablet. =J= _c3_ 16 1