Marsh Collection, Peabody Museum. 



443 



87 



riorly, arid on either side of this is a deep longitudinal cavity 

 whose lateral boundary is furnished by the unusually dependent 

 edge of the transverse process, much as in the fox ; a third or 

 fourth cervical centrum exhibits an elongated, depressed form, 

 with strong median keel. The dorsals have elevated spines 

 and comparatively small centra. The lumbars increase rapidly 

 in size posteriorly ; they have large strongly-interlocking 

 zygapophyses, which exhibit distinct traces of the double 

 tongue and groove articulation ; they also develop distinct 

 anapophyses. 



The sacrum is relatively much longer and stouter than that 

 of the fox, and its transverse diameter is proportionally quite 

 as great, which latter fact would indicate a pelvic outlet of 

 goodly proportions. This, in connection with the proportional 

 size of the skull, is in marked contrast with the conditions in 

 Dromocyon previously pointed out (p. 424). It may be here 

 remarked that the same proportionally small pelvic outlet 

 associated with the large head is also 

 true of some species, at least, of 

 Hycenodon. There are three coossi- 

 fied vertebrae in the sacrum, the two 

 anterior only of which contribute to 

 the formation of the auricular process 

 for the attachment and support of the 

 ilium — an essential and very constant 

 feature of the Carnassidentia. Among 

 the Marsupials generally, only one of 

 the vertebrae, the anterior, furnishes 

 this support, while in the living Insec- 

 tivora, as many as three vertebrae are 

 thus involved. The size of the sacrum 

 is apparently in relation to the long 

 and powerful tail, of which the numer- 

 ous caudal vertebrae give ample evi- 

 dence. These bones do not differ, as 

 far as can be observed, from the 

 caudals of other Creodonts. 



Of the appendicular skeleton, many 

 parts are preserved. The scapula, 

 while represented by numerous pieces, 

 is not sufficiently complete to furnish 

 any information of its general form 

 or outline. The glenoid cavity betrays 

 some resemblances to that of the 

 opossum, in the extent of the trans- 

 verse diameter and the large size of 

 the coracoid. In this latter feature, 



Figures 87, 88.— Eight 

 humerus of Sinopa agilis 

 Marsh ; front and proximal 

 end views ; three-fourths 

 natural size. (Cotype.) 



