218 



PROrEEDINOS OF THE NATIONAL MUSEUM. 



VERTEBRAL COLUMN, DESCRIPTION AND COMPARISONS. 



Cervicdl vertehrse. — The atlas is short with wide transverse processes, 



which are well expanded anteriorly, 

 but not extended posteriorly as 

 niiucih as in most modern carnivora. 

 The posterior opening of the ver- 

 tehrarterial canal faces backward 

 on the posterior maruin of the 

 tranverse process, as in all carniv- 

 ora except the Miocene and later 

 dog's. The remaining features are 

 It nearly resembles Ilyxnodon in 



JTlfi. 7.— SlNoPA GRANHERI, ATLAS VIEWED KROM 

 ABOVE, NAT. SIZE. .«./. FORAMEN FOR EXIT OF 

 1st SPINAL NERVE. 



v.a.f 



Fig. 8.— Sinopa grangeri, axis ver- 

 tebra, SIDE VIEW, NAT. SIZE, od, 



ODOKTOU) process; yza, posterior 



ZYGAPOPHYSIS; .s, NEURAL SPINE; 

 tr, TRANSVERSE PROCESS; V. a. f., 

 VERTEBR ARTERIAL FORAMEN. 



those usually found in Carnivora 

 proportions and form; in the cat the trans- 

 verse processes have the same shape and 

 position, but the body is a little longer; in 

 Canis and Dap/iamics the transverse proc- 

 esses extend more posteriorly; in Viverra 

 the body is considerably longer, the trans- 

 verse processes more posterior and less 

 expanded. In the opossum and hedgehog 

 the form of the processes is different and 

 the vertebral artery does not perforate the 

 bone. 



The axis is long, with high neural spine of 

 the characteristic carnivore form, expanded 

 into a broad plate extending forward as far 

 as the tij^ of the odontoid and ending posteriorly in a stout backwardly 

 directed spine. It is longer than in Jh/^uodon 

 but somewhat shorter than in Dap/td-vi's, and 

 shows no important distinctions from either. 



The remaining cervicals, except the seventh, 

 have short spines, transverse processes with the 

 inferior laminaB expanded into broad plates, and 

 superior lamiiue absent on the anterior ones, but 

 moderately developed on the sixth. In the Car- 

 nivora the superior lamiiue are generally dis- 

 tinct upon the third to sixth vertebra?, succes- 

 sively increasing in size. In the opossum the 

 arrangement is more as in Siiiojya^ except that 

 the inferior lamiiue are less expanded. In 

 iJaphanus the upper laminte are developed upon 

 the fourth, tifth, and sixth; in Or w/*^ upon fifth 

 and sixth; in Felida^ and Vixerridje upon all four. 

 In the Macha'rodonts the superior lamina is not distinct iipon any but 

 the sixth, but the inferior lamina is less broad and plate-like. 



Fig. 9.— Sinopa grangeri, 

 sixth cervical vertebra, 

 NAT. SIZE, SIDE VIEW, aza., 



ANTERIOR ZYGAPOPHYSIS; 

 il., INFERIOR LAMELLA OF 

 THE TRANSVERSE PROCESS; 

 pco, POSTERIOR ZYGAPOPHY- 

 SIS; ,S, NEIKAL SPINE, AND 

 Sl., SUPERIOR LAMELLA. 



