lyon] the hares and their allies 415 



lagus are entirely similar in form and position to these bones 

 in any of the Leporidse, as detailed in the general account of the 

 wrist and the hand (page 378). 



Pelvis Olid Lozi'cr Extremity. — The innominate bone in BracJiv- 

 lagtts is smaller than it is in other genera. The anterior part of 

 the ilium is of the narrow type with the antero-superior angle 

 obliquely rounded off, in these respects resembling Sylz'ilagits and 

 Oryctolagus. A tubercle in front of the acetabulum is more promi- 

 nent in Brachylagus than in the other genera. The descending 

 ramus of the pubis is slenderer, and the distance from the tuberosity 

 of the ischium to the nearest edge of the obturator foramen is rela- 

 tively shorter than it is in other Leporidse. The anterior edge of the 

 acetabulum is about equidistant between the extreme anterior and 

 posterior points of the os innominatum. 



The femur, tibia, and fibula (pi. xcix, 8) of Brachylagus. are 

 typical for the family as detailed in the general account (page 382) 

 and show nothing that is peculiar for the genus, but the fibula fuses 

 with the tibia at a point relatively nearer the middle than it does in 

 most of the genera. The femur is apparently relatively more slender 

 than in the other genera. 



The greatest length of the foot (pi. c, 3) in Brachylagus, unlike 

 that of most of the skeletons except Sylvilagits, No. 94,197 from 

 Nevada, is greater than the greatest length of the tibia. The basal 

 width of the metatarsals is contained about two and one-half times 

 in the length of the third metatarsal. The combined lengths of the 

 three phalanges approximately equal the length of the metatarsal 

 to which they are attached. 



So far as known the genus Brachylagus contains but a single 

 species, B. idahoensis, represented by two skeletons and several skulls. 



Brachylagus is a very well marked genus. Its peculiar teeth and 

 the ridge on the transverse process of the lumbar vertebrae are quite 

 unlike anything else among the Leporidse, although it would appear 

 from the published figures (Major, '99, pi. 37, fig. 17) of the 

 teeth of Ncsolagus from Sumatra that the latter has teeth resembling 

 those of Brachylagus. Aside from that, however, the two genera 

 have little in common. Apart from the structure of the teeth, Brachy- 

 lagus appears somewhat related to Microlagus, judging from the 

 skulls as a whole. The skeleton in general, aside from the reduced 

 number of caudal vertebrae and the ridges on the transverse processes 

 of the lumbar vertebrae, is much like the skeleton of Sylvilagus. 



