3^2 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



side attached to the rest of the vertebra, with a long sloping" or 

 usually concave posterior edge, and a more nearly vertical and 

 shorter anterior edge. 



In the following hares the spinous processes are perfectly tri- 

 angular, and are relatively not so high as in the typical form : 

 Roiucrolagus, Limnolagiis, Pronolagus, Poccilolagus. One skeleton 

 of the genus Sylrilagiis (No. 94,197, from Monitor valley, Nevada) 

 also has neural spines of this shape, although in the other members 

 of this genus which I have noted they are of the typical form. 



The anapophyses are very slightly developed on the lumbar 

 vertebrae of all hares. Their presence is usually indicated by a mere 

 ridge on the side of the vertebras, which ends in a small caudad 

 projecting tubercle. They are least developed in the skeleton 

 of Pronolagiis and are longest in the skeleton of a lop-eared 

 domestic rabbit, Orycfolagus ciiniciiliis. Here they are very 

 large, and in the three middle vertebrae of the lumbar series, 

 viz., third, fourth, and fifth, the anapophysis extends as far poster- 

 iorly as the posterior border of the metapophysis of the next suc- 

 ceeding A^ertebra. In the wild Oryctolagiis, however, this great 

 development of the anapophysis is not so pronounced, but it is much 

 larger than on the lumbar vertebrae of any of the other skeletons. 



Ventral spines, or hypophyses, or ridges indicating them, are found 

 on the first three lumbar vertebrae. The spines usually occur in three 

 lengths : In the genera Sylvilogus and Brachylagus the hypophysis 

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

 in length, and the shortest hypophysis is found on the third. Oc- 

 casionally in Syh'ilagns the first hypophysis is reduced to a 

 ridge and the last is sometimes lacking. In all the skeletons 

 of the genus Lepus the third lumbar vertebra bears the longest 

 hypophysis ; the first bears the shortest. In Romerolagus the first 

 hypophysis is the shortest, the second and third are subequal, the 

 third being a trifle the larger. In the skeletons of Limnolagus, 

 Pronolagus, and Oryctolagiis the hypophyses are more or less in- 

 jured. It would appear, however, in these genera that the second 

 hypophysis is the longest. 



Sacral Vcrtcbrcc. — The number of sacral vertebrae in the Leporidae 

 varies from three to five, according to the age of the individual, 

 four being the usual number. The two anterior vertebrae of the 

 sacrum are the only ones entering into the formation of the sacroiliac 

 joint. The remaining vertebrae are progressively smaller and 

 resemble in shape the anterior caudal vertebrae. 



The first sacral has a large neural spine, vertical or inclined 



