161 



and tapering, that of the first being the more so. The claws of 

 the third and fourth are very large and strong, the former being 

 15 mm. X 4 mm., of uniform width and ending bluntly ; the 

 fourth, shorter but much wider at the base and triangular in 

 shape, tapers rapidly to a point. The fifth is represented exter- 

 nally by a broad and stumpy nail. 



The hind limbs (PL II., III., IV.) are also short and strong, 

 and have the plantar surface of the pes turned almost directly out- 

 wards, so that its fifth digit lies in front. This surface is much 

 wrinkled into several large baggy folds directed obliquely across 

 the sole, and is covered with a leathery skin like that of the palm, 

 which extends as far as the base of the nails, and even encroaches 

 on their plantar surface. The claws of the hallux, second, third 

 and fourth digit are concave on their plantar surface, and those of 

 the third and fourth are curved both outwards and backwards. 

 The fifth is represented by a strong and short stumpy nail, 

 rather like that of the corresponding digit in the manus, and lies 

 more towards the palmar surface than the others. The length 

 of the fourth is six mm., and the others diminish in length 

 towards the hallux. On the dorsal (inward) surface the course 

 of the first four digits can be seen through the integument, and 

 the skin covering them is free from hair as far upwards as the 

 base of the metacarpals. 



OSTEOLOGY. 



THE SKULL. 



(PL YL, fig. 1 ; PL YII., figs. 1 and 2.) 



The outline of the skull, including the zygomata, is conical, 

 with the occipital region expanded and well developed ; anteriorly 

 it tapers to the region of the exterior nares which are terminal, and, 

 owing to the overhanging nasal bones, these orifices open down- 

 wards and forwards and have a quadrangular outline. The occip- 

 ital plane is flat and almost vertical. Within the zygomatic arches 

 the skull is constricted about the mid-region of the orbito-temporal 

 foss?e, widening again considerably in the region of the juncture 

 of the lachrymal and superior maxilla on each side. The vertex 

 is smooth, without any median ridge and considerably flattened, 

 and the bones throughout are exceedingly thin, papery and 

 translucent. 



The occipital foramen is almost circular, but slightly compressed 

 laterally by the encroachment of the condyles. These also are 

 compressed laterally and have their long axes running parallel and 

 almost truly antero-posteriorly. From behind forwards (or from 

 above downwards) their contour is almost semicircular, and their 

 articular surfaces look backw\ards for their upper, and downwards 



