FISCHER ON THE PELYIS OF THE MAMMALIA. 13 



is 5'" ; in the cercopithecus paniscus, 1" 3'" ; in the lemur mongoz, 1" 6'". 

 Each vertebrae may be divided into a body, an inferior and a superior extre- 

 mity. The body is oblong, and includes four unequal surfaces. The upper 

 extremity, thicker than the inferior, has a rounded articular surface, uniting 

 to itself the preceding vertebrae. Around this surface there are tuberculous 

 processes. Two of these processes are divided, so that in the terminating ver- 

 tebrae there are six processes present. The lower extremity of the vertebrae 

 ends in an articular surface, around which three processes only are placed. 

 The tuberosities, placed around the joints or articulations, looking upwards, 

 evidently correspond to, or originate in, the oblique and transverse .processes of 

 the superior vertebrae, altered in their form. 



In the cercopithecus, already so often mentioned, the elongated vertebrae of 

 the os coccygis are evidently similar to those described in the former para- 

 graph, at that place where they rise above the posterior margin of the pelvis. 

 In the tubercle placed around the superior articular surface, itself inferior and 

 bifid, the two first vertebra of the more distinct portion of the tail, properly 

 so called, as well as the three other vertebra?, placed between the beginning 

 of the distinct tail, and the sacral vertebrae, have a spinous process, quite 

 similar to that which, in the dorsal vertebrae, looks backwards. This little 

 bone is forked with two diverging crura, leaving between them a foramen, 

 resting on the tubercles around the articulation, and looking towards the ab- 

 domen with the apex downwards. These abdominal spinous processes are 

 united to the bodies of the vertebrae by a cartilage, or rather to the interme- 

 diate fibro-cartilage than to the vertebrae themselves. It is worthy of being 

 mentioned, that these same abdominal spinous processes are not only found in 

 the mus and the mustela, but also in the dolphin. Tyson, in his work on the 

 Anatomy of the Porpoise, describes them in these words " Besides the pro- 

 cesses already mentioned, I find on the abdominal aspect of the vertebrae, 

 other processes opposite to the dorsal spinous processes, connected with their 

 intermediate fibro-cartilages. They consist of two slender little bones, joined 

 at one extremity, and separated at the other, so that their bases form a series 

 of foramina, through which run a number of blood vessels, in a manner quite 

 similar to the medulla spinalis in the canal formed by the dorsal spinous pro- 

 cesses. These processes, like all others of the vertebrae, gradually decrease 

 as they approach the first caudal vertebrae, until at last they entirely disap- 

 pear. A^titenreith. 



Section 7. Ossa innominata. These bones, before they reach the adult 

 state, are composed, as all agree, each of three bones, first, the os ilium ; 

 second, the os pubis ; third, the os ischium. 1. The os ilium, in the quadru- 

 niana differs widely from that of man.* For these bones do not diverge so 

 much, nor do they form a cavity so large and distinct as in man, but ascend, 

 diverging only a little as it were, upwards from the middle of the acetabulum ; 

 they have a triangular form, and are slender and much longer than in man. 

 The body of the os ilium, or at least that portion of it which, with the op 

 ischium and the pubis, assists in forming the acetabulum, is broader in the 

 quadrumana than in man, when compared with the superior crest, for the crest 

 in the quadrumana is broader than the body only by some lines ; whereas in 



* W. Joseph! 1. c., Tab. v , Fig. 2. P. Camper 1. c., Tab. iii., Fig. 7. 

 D 



