OCR Text |
Show 1875.] MR. G. E. DOBSON ON THE GENUS SCOTOPHILUS. 369 It has been suggested, however, by Dr. W. Peters, who has pointed out these facts*, that the name Scotophilus should be retained for those Bats inhabiting the Eastern Hemisphere, hitherto known as Nycticeji, which differ in many important respects, requiring generic separation, from the genus represented in the N e w World by Nyc-ticejus crepuscularis, Le Conte, which possesses, numerically, the same dentition. I have adopted Prof. Peters's suggestion, because zoological literature is thereby spared the burden of a new generic name. It still remains, however, to supplement the very imperfect and misleading original definition of Scotophilus by one from which the characters of this genus may be known and its members readily recognized. This is especially necessary ; for since a large number of species representing very different groups were included by Dr. J. E . Gray under the common generic title Scotophilus^, this name has been indifferently applied, by English and American zoologists especially, to almost every species of Bat belonging to the family Vespertilionida of which the dental formula was known or suspected to represent less than thirty-eight teeth, ScOTOPHtLUS. Muzzle short, obtusely conical, smoothly rounded off, naked : nostrils close together, opening by simple lunate apertures in front or sublaterally, their inner margins projecting: ears longer than broad, generally considerably shorter than the head, with rounded tips, the outer margin terminating behind the angle of the mouth in a distinct convex lobe; tragus tapering, generally subacutely pointed and curved inwards. Tail shorter than the head and body, Contained, except the terminal rudimentary vertebra, within the interfemoral membrane: calcaneum weak; wings attached or close to the base of the toes. Fur generally short and nearly confined to the body; wing- and interfemoral membranes very thick and leathery. Skull thick, with prominent crests: occipital and sagittal crests often forming at their junction behind a thick projecting process from which the skull slopes evenly downwards and forwards to the end of the nasal bones in front; occiput concave, with prominent occipital crest; facial bones much shortened in front of infraorbital foramina, which are large and well defined; the bony palate very narrow behind last upper molar, extending backwards as far as the middle of the zygomatic arches; basioccipital between cochleae broad; cochleae partially concealed by the tympanic bullae; paroccipital and mastoid processes well developed, prominent. 1 1 11 11 *' '•' Dentition.-Inc. -j-; C. yj-j; P m . if^; M . .^. A n additional external incisor, on each side, above, in the young. Upper incisors long, unicuspidate, acute, close to the canines by their * Monatsb. Akad. Wissensch. Berl. 1866, p. 679. t " Revision of the Genera of Bats," Mag. Zool. & Bot, ii. pp. 497, 498 (1838). PROC. ZOOL. Soc-1875, No. XXIV. 24 |