Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/426

Rh MAMMALIA [iXSECTJVOKA, tail, and a proportionally longer snout. Urotrichus, with pm |, and Neiirotrichus (subg.), withjm-f, are represented by two small Mole- like species, externally resembling one another closely, from Japan and North America respectively. Of Uropsilus, U. soricipes, from the borders of Tibet, is a very interesting species, having the external form of a Shrew but the skull of a Mole. Subfamily II. Talpinae (True Moles). Clavicles and humeri very short and broad ; manus with a large os falciforme. A. Froiit upper incisors much larger than the second pair (New- World Moles). a. i %, c, pm $, m f ; extremity of nose simple. Scalops. b. i, c , pm , m f ; extremity of nose simple. Scapanus. c. i f, c $, pm $, m % ; extremity of nose with appendages. Condylura. B. Front upper incisors scarcely larger than the second pair (Old-World Moles). d. i f, c {, pm, mf ; manus as in Urotrichus. Scaptonyx. e. i or f, c {, pm |, m f ; manus very broad. Talpa. Scaptonyx, with a single species S. fusicaudatus, from west China, connects Urotrichus with the true Moles. Talpa includes seven species, of whi .-h the Common Mole is a familiar example. See MOLE. Family POTAMOGALID.E. Tnsectivora with a small brain case, without post orbital processes or zygomatic arches, and with annular tympanics not forming bullse. There are no clavicles ; the pubic bones are connected by a liga ment, and there is no true symphysis ; the intestine has no caecum ; the tibia and fibula are united low down ; and the upper true molars have broadly V-shaped cusps presenting characters inter mediate between those of the preceding and succeeding families. a long naked tail, feet formed for running, and the body clothed with long, coarse fur. The position of the mammae quite behind on the buttocks is unique among Insectivora. The upper front incisors are much enlarged, and with the other incisors, canines, and premolars closely resemble those of Myogale ; the second lower incisors are, as in PIG. 60. Potamogale ve .ox. x i- Allman, Trans. Zool. Soc., vi.. pi. i. Potamogale, i f, c, pm |, m f, with P. velox. This most in teresting species inhabits the banks of streams in west equatorial Africa, and its whole structure indicates an aquatic life. It is nearly 2 feet in length, the tail measuring about half. The long cylindrical body is continued uninterruptedly into the thick laterally compressed tail, the legs are very short, and the toes are not wobbed, progression through the water evidently depending wholly on the action of the powerful tail, while the limbs are folded inwards and backwards. The muzzle is broad and Hat, and the nostrils are protected by valves. The fur is dark brown above, the extremities of the hairs on the back being of a metallic violet hue by reflected light, beneath whitish. Geogalc, i f, c , pm $, m f , with G. aurita, a small Mouse-like species from Madagascar, agrees closely with Potamogale in the general form of the skull and teeth ; the tibia and fibula are distinct, but it is not known whether a clavicle exists or not, and the material at present available is insufficient to definitely fix the natural position of the species. Family SOLENODONTID.E. Insectivora with a small brain case constricted between the orbits, and without post-orbital processes or zygomatic arches. The penis is carried forwards and suspended from the abdomen ; the testes are received into perineal pouches ; the mammary glands are post-inguinal ; the uterine cornua end in csecal sacs ; the intestine has no caecum ; the tympanics are annular ; the upper true molars have V-shaped crowns ; the symphysis pubis is short ; and the tibia and fibula are distinct. SoUnodon, i -|, c f, pm f, m f, with S. paradoxus and S. cubanus, from Hayti and Cuba respectively, alone represents the family. These species, which differ chiefly in the colour and quality of the fur, have each a remarkably long cylindrical snout, FIG. 61. Solcnodon cubanus. x J. Peters, Abh. Akad. Btrl. Potamogale, much larger than the anterior pair, and are deeply hollowed out internally. While thus apparently showing relation ship with the Talpidae, the form of the crowns of the molar teeth connects them with the next family. Family CENTETID^E. Insectivora with a small cylindrical brain case not constricted between the orbits, and without post-orbital processes or zygomatic arches. The penis is pendent and retractible within the fold of the integument surrounding the anus ; the testes are abdominal ; the mammary glands are thoracic and ventral ; the uterine cornua are terminated by the Fallopian tubes ; the intestine has no caecum ; the tympanics are annular ; the molars have V-shaped crowns ; the pubic symphysis is short, and the tibia and fibula separate or united. All the known species are limited to Madagascar. Subfamily I. Centetinse. Tibia and fibula distinct ; testes near kidneys ; fur with spines. FIG. 62. Skull of Centetes ecaudatus (reduced). Centctcs, i f or f, c }, pm f, m f or |-. The single species, C. ecaudatus, the well-known taillessGround-Hog of Madagascar, attains a total length of from 12 to 16 inches, and is the largest known Insectivore. The adult males have exceedingly long canines, tho extremities of the lower pair being received into pits in front of the upper canines. It is probably the most prolific of all mammals ; as many as twenty-one young are said to have been brought forth at a birth. The young have strong white spines arranged in longi tudinal lines along the back, but these are lost in the adult ani mal, which is provided only with a nuchal crest of long rigid hairs. ffemicentetes, i f, with H. semispinosus and H. nigriceps, is dis tinguished by the persistence of the third upper incisor, and by the form of the skull. The two species are very much smaller than C. ecaudatus, and the dorsal spines are retained in the adult state. Ericulus, i f, has E. setosus, a remarkable Hedgehog-like species having the whole upper surface and even the short tail densely covered with close-set spines. The facial bones are much shorter than in any of the preceding genera, and the upper front incisors are elongated as in Erinaceus. Judging from the slight develop ment of the cutaneous muscles compared with those of the true