LEPUS 235 



longest of the series ; and each has a length equal to that of its 

 centrum, plus half the length of the centrum just anterior to it. 



There are thirteen to fourteen caudal vertebrae. 



The ribs have the spine-like portions of the tubercles well 

 developed, the last pair bearing these tubercles being the eighth. 

 The second, third, fourth, fifth, and sixth pairs have the ventral 

 halves of their shafts very flat and broad, so that the greatest 

 width of one of these ribs, just behind the tubercle, is very much 

 less than the width of the shaft in its lower portion. Seven 

 pairs of ribs articulate with the sternum. The sterno-costal 

 cartilages are very short and wide as compared with those of 

 Oryctolagus, 



The clavicles are imperfect, as throughout the family (see 

 above, p. 159). 



The scapula; are relatively broad with their superior borders 

 relatively convex, the antero-superior angles relatively rounded, 

 and the supra-spinous fossae relatively broad. 



The ulnae are reduced in size along the centres of their shafts, 

 and, except at their lower extremities, lie almost entirely behind 

 the radii, which latter are rather long and slender, and in length 

 may equal or exceed their humeri. 



The fibulae are ankylosed to the tibiae. 



In some exotic species the lengthening of the external ears 

 has been carried to such an extraordinary degree as to have 

 inspired the belief that these organs could not have been 

 developed solely for purposes of hearing. So good a field 

 naturalist as Thompson Seton can imagine no better use for 

 them, in the North American Lepus campestris> than as a 

 possible shelter to the back of the animal as it sits in its form 

 during heavy rains ; and, more than two thousand years ago, the 

 celebrated Greek soldier and sportsman Xenophon (born about 

 B.C. 430), in a treatise on hare-hunting entitled Cynegeticus, sup- 

 posed that, since the tail is so short as to be useless for steering 

 purposes at high speed, an ear on one side might be laid down 

 and thus assist in turning the body when sharply pursued. 

 Modern coursers have also noticed this movement, and say that 

 a hare when coursed and hard pressed by greyhounds, turns 

 down the ear on the side to which she is going to turn, and 

 that she does this in order the better to catch the sound of her 



