lvon] the hares and their allies 405 



The sacrum of Orycfolagiis differs in no way from the description 

 given in the general account, p. 362. 



The caudal vertebrte are about seventeen in number, one being of 

 the first form (see p. 363), six to eight of the second, and the last 

 eight or nine are the rudimentary elongated centra, without neural 

 canal or processes. 



Stcrniun and Ribs. — The sternum (pi. xc\', 5) in Oryctolagiis 

 is in general as in Lcpiis. The presternum is more conspicuously 

 keeled ; the first pair of ribs attached just anterior to its middle. The 

 mesosternal segments are more compressed from side to side than 

 they are in Lcpits. The last is much shorter than any of the other 

 mesosternal segments. The xiphisternum is large and stout, longer 

 than the presternum, its posterior end about as much enlarged as 

 its anterior. 



There is nothing by which the ribs of Oryctolagiis can be distin- 

 guished from the ribs of Sylz'ilagiis. The shafts of the anterior ribs 

 are scarcely enlarged in their ventral portion. Spine-like portions 

 of the tubercles of the ribs are well developed, and are last seen in 

 the eighth pair. 



Shoulder Girdle and Upper Extremity. — The scapula (pi. xcvii, 

 3) of Oryctolagiis is dift'erent in form from the same bone in Lepiis, 

 Rouierolagiis, and Pronolagiis, but shows nothing tangible by 

 which it can be distinguished from the scapulae of the other genera. 

 It is relatively narrow, the superior border relatively convex, the 

 antero-superior angle moderately prominent, and the supraspinous 

 fossa relatively narrow, as compared with the scapula of Lepiis. 



Regarding the humerus of Oryctolagiis there is nothing by which 

 it can be distinguished from the humeri of many of the other genera. 



The form, relative sizes, and positions of the radius and ulna are 

 nearly alike in Oryctolagiis, Sylvilagns, Pronolagiis, and Lininolagiis; 

 that is, the ulna is not reduced in the middle of its shaft and is 

 situated external to the radius rather than bshind it. In Oryctolagiis 

 the ulna is somewhat heavier than the radius and both bones ars 

 rather heavier than they are in the other genera mentioned above. 

 The radius is equal to the humerus in length. 



The carpus, the metacarpus, and the phalanges of Oryctolagiis are 

 entirely similar in form and position to these same bones in any of 

 the Leporidse, as detailed in the general account of the wrist and hand 

 (P- 378). 



Pelvis and Loz^'cr Extremity. — The os innominatum has about the 

 same general form in Oryctolagiis and in Syli'ilagus. The ilium is 

 not wide and shovel-like except in the lop-eared domestic. The 



