4^4 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



extending from the internal face about three-quarters the distance 

 across the tooth. The adjacent edges of this angle are almost in 

 contact with one another throughout their whole extent and crenated. 

 In the second, third, and fourth lower molariform teeth the lateral 

 diameter of the posterior half of each tooth is about four-fifths the 

 lateral diameter of the anterior half of the tooth. The last upper 

 molar is very small, with an elliptical outline. The last lower molar 

 is also small, consisting of a larger anterior elliptic portion and a 

 smaller posterior portion, circular in outline. 



J^crtchral Column. — The cervical vertebrae (pi. xcii, 6) of 

 Oryctolagiis have nothing to distinguish them from the same series 

 of vertebrae of several other genera, being noticeably different onl\ 

 from the two extremes, Lcpits, with elongated cervicals on the one 

 hand, and Pronolagiis, with more shortened ones, on the other. The 

 cervicals are uniformly shortened, the costal processes project 

 relatively far from the sides of the centrum ; the anterior and the 

 posterior spines of these processes are less prominent than they are 

 in Lcpiis. The true transverse process is more conspicuous and is 

 often found to project laterally from the side of the fifth vertebra. 



The length of the neural spines in the anterior thoracic region is 

 about three times the length of a centrum. The anticlinal vertebra 

 is the eleventh, on the lop-eared domestic it is the tenth, however. 

 Metapophyses are well developed on the tenth, eleventh, and twelfth 

 thoracic and are indicated on the ninth by small tubercles. 



The lumbar vertebrae (pi. xciii, 4, 5) are scarcely distinguishable 

 from the same series of vertebrae in Sylvilagus. The transverse 

 processes do not arise abruptly from the anterior half of the lateral 

 aspect of the centra, but from the whole side, so that the angle be- 

 tween the process and the centrum is partly filled in with bone, but 

 in no way comparable to the filling in that takes place in Limnolagiis 

 and in Romerolagiis. Anapophyses are best developed in this genus 

 of all the Leporidae. In the skeleton of the lop-eared domestic, these 

 processes are very large ; in the three middle vertebrae of the lumbar 

 series, the third, fourth, and fifth, the anapophyses extend as far 

 caudad as the posterior border of the metapophyses of the next suc- 

 ceeding vertebra. In the two skeletons of wild Oryctolagiis, how- 

 ever, this great development of the anapophyses is not so pro- 

 nounced, but they are much larger than they are on the lumbar 

 vertebrae of any of the other skeletons. 



The hypophyses are injured in the skeletons of the wild animals, 

 but from what remains of them it would appear that the second 

 hypophysis is the longest, as it is in the lop-eared domestic. 



