PART III (INSECTIVORA).

The entozoa of insectivorous mammals, though sufficiently numerous, are not important practically. The common hedgehog (_Erinaceus europæus_) is infested by four flukes (_Distoma pusillum_, _D. trigonocephalum_, _D. caudatum_, _D. linguæforme_), and also by three thorn-headed worms (_Echinorhynchus napæformis_, _E. amphipachus_, and _E. major_). Two tapeworms are also known (_Tænia compacta_ and _T. tripunctata_). More attention has been paid to the round worms. A species of strongyle (_S. striatus_) infests the lungs, the male being readily distinguished by its nearly round hood. A second species of strongyle has been mentioned by Diesing, but it is more than doubtful. The lungs are also infested by a small trichosome (_Eucoleus tenuis_ of Dujardin); another species of the genus (_Trich. exiguum_) infesting the stomach and small intestine. As the _Trichina spiralis_ has been repeatedly reared by myself and others in the hedgehog, the little flesh-worm must also be noticed in this place. _Physaloptera clausa_ occupies the stomach, and a minute Ascaris (_A. pusilla_) is found in cysts of the peritoneum. According to Wedl, the intestine of the Egyptian hedgehog (_Erinaceus auritus_) is infested by another worm, which he calls _Pterygodermatitis plagiostoma_. This is allied to Froelich’s genus _Rictularia_. As regards the mole (_Talpa europæa_), two flukes have been described (_Distomum flexuosum_ and _Monostomum ocreatum_), also two round worms, namely, _Ascaris incisa_, occupying the peritoneum, and _Spiroptera strumosa_ in the cavity of the stomach. Dr Schneider places the latter with the Filariæ. A little tapeworm (_Tænia bacillaris_) infests the small intestines, and a larval cestode occupies the liver and subcutaneous connective tissues. This is the well-known _Cysticercus talpæ_, which Leuckart and others have referred to as being the scolex or juvenile state of _Tænia tenuicollis_ infesting weasles (_Mustelidæ_). The Cysticercus is also found in _Arvicola arvalis_. In regard to the shrews, many species of fluke have been described as occupying the intestines. In _Sorex araneus_ and _S. leucodon_, the _Distoma migrans_; in _S. constrictus_, the _D. exasperatum_; in _S. tetragonurus_, the _D. corrugatum_ and _D. rubens_; the last-named fluke, with two others (_D. instabile_ and _D. truncatum_), being also found in Daubenton’s shrew. The tapeworms are numerous--_Tænia neglecta_, _T. furcata_, _T. uncinata_, _T. pistillum_, _T. tiara_, _T. scalaris_, _T. scutigera_. With the exception of the last named, all these forms occur in the common shrew. According to the investigations of M. Villot the cysticercal stage of _T. pistillum_ is to be found in the glow-worm (_Glomeris_). This scolex (_Staphylocystis micracanthus_, Villot) multiplies by proliferation, and in this way the swallowing of a single intermediate host may result in the formation of a hundred or more tapeworms. Another species of Staphylocystis (_S. biliarius_) is considered by Villot to be the larval source of _T. scutigera_ and _T. scalaris_, which are perhaps identical species. A small Echinorhynchus (_E. appendiculatus_), found in the intestines and also encysted in the mesentery of the shrew, in like manner becomes transferred to the stomach of the fox. The nematodes of shrews possess little interest. In the common shrew the only species known are _Trichosoma splenaceum_ and an immature worm, whilst in _Sorex tetragonurus_ we have _T. incrassatum_, occupying the tunica vaginalis of the testis, and _Strongylus depressus_ in the intestines. Not many other insectivora appear to have been studied in relation to their internal parasites. A larval cestode has been noticed in the Russian musk rat (_Mygale_), and also a tapeworm (_Tænia sphærocephala_) in the golden mole (_Chrysochloris_). Several flukes and a tapeworm have been found in the water-shrews (_Sorex fodiens_), but, so far as I am aware, nothing has been done in connection with the parasites of the _Macroscelidinæ_, of the Banxrangs (_Tupainæ_), or of the Tanecs (_Centites_) and their allies. The entozoa of the star-nosed and shrew moles of North America (_Condylura_ and _Scalops_) also deserve attention. From the last-named genus (_S. canadensis_) Prof. Leidy obtained a single male spiroptera. It occupied the stomach and was only half an inch in length.

BIBLIOGRAPHY (No. 44).--_Leidy_, “_S. scalopsis canadensis_,” ‘Proc. Phil. Acad.,’ 1851, p. 156.--_Linstow_, “_D. cordatum_, Einige neue Distomen (u. s. w.),” ‘Arch. für Anat.,’ 1873, s. 95.--_Molin_, ‘Una Monografia del genere Physaloptera,’ Wien, 1860 (p. 7, “_P. clausa_,” and p. 31, “_P. limbata_”).--_Idem_, ‘Nuovi myzelmintha,’ Wien, 1859, p. 10, Spec. No. 8.--_Idem_, ‘Una Monogr. del genere Spiroptera,’ Wien, 1860, p. 25, Spec. No. 22.--_Schneider_, ‘Monogr. der Nematoden,’ Berlin, 1866, s. 103, Spec. No. 39.--_Stieda_, in ‘Troschel’s Archiv,’ 1862, “Description and figs. of _Tænia uncinata_ and _T. furcata_ of the Shrew.”--_Thomson_, art. “Ovum,” in ‘Todd’s Cyclop. of Anat. and Phys.,’ contains figs. and description of _T. pistillum_ (from Dujardin), vol. v, p. 28.--_Villot, A._, “On the Migrations and Metamorphoses of the Tapeworms of the Shrews,” in ‘Ann. of Nat. Hist.,’ March, 1878, from ‘Comptes Rendus,’ Nov. 19, 1877, p. 971.--_Wedl, K._, “Zur Helminthenfauna Ægyptens,” ‘Sitzungsb. d. math.-naturw. Classe’ (u. s. w.), Bd. xliv, Abth. i, s. 464.