438 THE ANATOMY OP VEETEBEATED ANIMALS. 



sijinoiis ancl transverse processes. At about the eightli, a 

 mammillary process, or metajjophysis, becomes obvious ; 

 and, in the succeeding vertebrae this increases in length and 

 strength, till in the lumbar region it becomes as long as 

 the spinous process. In the last lumbar, it is short, and 

 in the sacrum, it is obsolete, but it is traceable through 

 the series of the anterior caudal vertebrae. Accessory pro- 

 cesses, or anapophyses, are observable in the last dorsal 

 and foui" or five anterior lumbar vertebrae. The trans- 

 verse processes of the lumbar vertebrae are exceedingly long, 

 and that of the first lumbar is bifurcated at its extremity. 

 These transverse j)rocesses give attachment above, to the 

 sacro-lumbalis, and below, to the psoas major, both which 

 muscles are very large ; while the heads of the longissimus 

 dorsi are attached to the long metapophyses. The great 

 mass of these extensor and flexor muscles of the spine, and 

 the leverage afforded by the mode of their attachment to 

 the long processes of the vertebrae, would seem to be re- 

 lated to the leaping and scratching movements of the 

 Rabbit. Strong median processes are developed from the 

 ventral faces of the centra of the three anterior lumbar 

 vertebras ; these give attachment to the ciiu-a of the 

 diaphragm. 



The tiibercles of the second to the eighth ribs inclusively 

 are prolonged into spiniform processes, which give attach- 

 ment to the tendons of the longissimus dorsi. There are 

 five stemebrae and a long xiphoid process. The manubrium 

 is long, narrow, deep, and keeled inferiorly. 



In the skull, the great supra-orbital processes of the 

 frontal are to be noted. The presphenoid is high and 

 greatly compressed from side to side, so as to form a thin 

 septum between the orbits, and the optic foramina ran into 

 one, as in some Seals. The tympanic and the periotic are 

 ankylosed together, but remain distinct from the adjacent 

 bones, and are merely held in position by abutting against 

 the basi-sphenoid on the inner side and by the post-tym- 

 panic hook of the squamosal on the outside. The tympanic 

 is prolonged iipwards and outwards into a tubular meatus. 



