lvon] the hares and their allies 399 



of the anterior half of the tooth. The last upper molar is small with 

 an elliptic cross section. The last lower molar is a small double 

 cylinder in form, the anterior half of which is farger and elliptic in 

 section, the posterior half terete. 



Vertebral Coluiini. — The cervical vertebrae (pi. xcii, 5) of Syk'i- 

 lagiis have nothing to distinguish them from the same vertebrae 

 of many other genera, being noticeably different from those of Lcpns 

 and Pronolagns only. The cervicals are uniformly shortened, the 

 costal processes project laterally farther from the sides of the 

 centrum, the anterior and the posterior spines of these processes are 

 less prominent, than in Lcpns. The true transverse process is more 

 conspicuous and is often found to project laterally from the side of 

 the fifth vertebra. 



The length of a neural spine in the anterior thoracic region is about 

 twice the length of the centrum, to which it is attached. The anti- 

 clinal vertebra is usually the eleventh, but often the tenth. ^leta- 

 pophyses are usually seen only on the tenth, eleventh, and twelfth 

 thoracic vertebrae, sometimes on the ninth. 



The lumbar vertebrae (pi. xciv, 14) are scarcely distinguishable 

 from the same in Oryctolagus. The transverse processes instead of 

 arising abruptly from the anterior half of the lateral aspect of the 

 centra as they do in Lcpns, arise from the whole side, so that the angle 

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

 this is not comparable to the filling in that takes place in Liuinolagus 

 and in Roiiicrolagus. True anapophyses are lacking, the neural 

 spines and metapophyses show nothing of interest. The hypophysis 

 on the second lumbar is the longest, that on the first is next in length, 

 and the shortest is found on the third. Sometimes the first hypo- 

 physis is reduced to a ridge and the third is lacking. 



The sacrum dift"ers in no way from the description given in the 

 general account. 



The caudal vertebrae vary from eleven to fifteen in number. The 

 larger number is the more usual. Of the different forms (see p. 363) 

 of vertebrae in this region, one, or often two, is of the first form ; five 

 to seven of the second, usually six ; four to seven of the last form, 

 usually six or seven. The skeleton with the lowest number of 

 caudals, eleven, is Syknlagns inincnsis Thomas. The decrease takes 

 place in the last form, which is here reduced to four in number. 



Stcrnnui and Ribs. — The sternum (pi. xcv, 2) of Syli'ilagns 

 is not very characteristic. In general it resembles the sternum of 

 Lcpns. The presternum is relatively larger, the keel less prominent 

 anteriorly. The first pair of ribs is attached just in front of its 



