lyon] the hares and their allies 413 



portion to which it belongs. In all the other genera the anterior and 

 posterior portions of the three lower molariform teeth are subequal 

 or nearly so. The enamel between the two portions of these teeth 

 is not crenated as in the other groups. 



Vertebral Coluuin. — The cervical vertebrae (pi. xcii, 3) of Brochy- 

 lagiis have practically the same form that they have in the large genus 

 Sylz'Hagiis, that is, they belong to the shorter tvpe. 



In the anterior part of the thoracic series of vertebrae, the length 

 of the neural spine is about equal to three times the length of the 

 centrum to which it is attached. The tenth thoracic is the anticlinal 

 vertebra ; its spine is abruptly broader than any of the spines in 

 front and is concave on its anterior and also on the posterior edge. 

 The anterior edge of the eleventh is slightly concave and is perpendic- 

 ular in its general direction ; the posterior edge is concave and slopes 

 backward and downw^ard from above. The spine of the last thoracic 

 is smaller than that on the eleventh and resembles in form the spines 

 of the lumbar series. Well developed metapophyses are found on 

 the last three thoracic vertebrae, and on the ninth this process is dis- 

 tinctly indicated by a small spine. The last two vertebras of this 

 series have rather well marked ventral ridges. 



The lumbar series of vertebrae (pi. xciv, 12) in Braclivlagiis is 

 quite different in some respects from the same series in the other 

 genera. The best distinguishing character is a prominent longitudinal 

 rounded ridge extending the length of the long axis of the transverse 

 processes. The process itself is rather long and slender, is rather 

 more curved and concave anteriorly than the lumbar transverse proc- 

 ess in the other genera. The longest process has a length of 

 one and a half times that of the centrum to which it is attached. 

 The process does not rise abruptly from the side of the centrum, 

 but slopes gently into it at the posterior angle of its attachment, 

 as in Syhc'ilagiis and in Oryefolagiis. The neural spines are low, 

 especially anteriorly. Anapophyses are slightly more developed on 

 the anterior three or four vertebrae of this series than they are in 

 other genera, except Orycfo/agiis. 



The sacral vertebrae are four in number and differ in no essential 

 respects from the same vertebrae in other genera. 



The caudal series of vertebrae is very short in Brachylagiis, the 

 total number being nine, the smallest that occurs in any genus except 

 Roiiicrolagiis, which has the same number, and .Xesolagiis which has 

 eight. The first two caudal vertebrae are long, wnth complete neural 

 arches, and resemble the last sacral vertebrae, the next three are 

 shorter, with rather wide transverse processes, the last four are 



