lyon] the hares and their allies 359 



seem to be more than individual, and the most that can be said is 

 that they are tendencies rather than fixed characters. 



The relative length of the neural spines in the anterior part of 

 the thoracic series of vertebrse varies fairly constantly as follows : 

 In Ronicrolagns, the length of an anterior neural spine is about 

 twice the length of the centrum of the vertebra to which it is at- 

 tached ; in Sylvilagus, BracJiylagiis, Limnolagus, Lcpus (Pcccilo- 

 lagiis), and Pronolagiis. the spine equals about two and a half times 

 the centrum ; in true Lcpus it is about three times the length of the 

 centrum, and in Macrotolagus and Oryctolagus it is a trifle over 

 three times. 



The position of the anticlinal vertebra varies between the tenth 

 and eleventh thoracic as follows : It is the tenth in Brachylagns, 

 ■Liuuiolagns, and Ronicrolagns: it is usually the eleventh in Lcpns, 

 Syh'Uagus, Oryctolagus, and Pronolagus, but in some cases it is the 

 tenth. 



Metapophyses are always found well developed on the last three 

 thoracic, but in Pronolagus, Limnolagus, and most of the members 

 of Lcpus, a well-developed metapophysis is also found on the ninth 

 thoracic ; this also happens frequently in the case of the genus 

 Sylvilagus. . But even those cases when the metapophysis is well 

 developed on the tenth and eleventh thoracic only, it is always in- 

 dicated by an ill-defined tubercle on the ninth. 



Lumbar Vertebra: (pis. xciii, xciv). — The seven lumbar vertebra 

 are large and elongated. Each is provided with a stout, broad, 

 spinous process, much shorter than the spines of the thoracic ver- 

 tebrje. The metapophysis is well developed in all the lumbar verte- 

 bras, and in the lumbar series nearly equals the spinous process in 

 size. Like the spinous processes, the metapophyses are directed 

 forward. On the anterior five lumbar vertebrse the anapophysis is 

 represented by a horizontal line ending posteriorly, usually, in a small 

 projecting spine. In some cases this little spine is practically absent, 

 while in others it is very well developed. 



The transverse processes of the lumbar vertebras are very large 

 and long, projecting downward and forward. The proximal end 

 arises from the anterior third or half of the side of the centrum. 

 The free extremity is usually enlarged, and in the more anterior 

 vertebrae of the lumbar series it is usually bifurcated. The total 

 length of a transverse process in the middle of the lumbar series 

 is usually equal to one and one-half times the length of the centrum 

 to which it is attached. 



