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PROCEEDINGS OF THE NATIONAL MUSEUM. 



pzn 



qxa 



FK;. 14. — SiNOPA GRANGEKI. SEV- 

 ENTH AXD SIXTEENTH CAVDAL 

 VERTEBRAE, SIDE VIEWS, NAT. 

 SIZE. aza, ANTERIOR ZVGAPO- 

 PHYSES: p.a, POSTERIOR ZYGAPO- 

 PHYSES; /)•, TRANSVERSE PRO- 

 CESS. 



their transverse plates so wide. The second sacral takes a minor part 

 in the iliac articulation by means of the forward end of its transverse 

 process. 



The caudals are preserved in series as far back as the seventeenth. 

 The first four have lar^-e. strongh' convex zygapophyses like those of 



the lumbars, long-, stout transverse processes, 

 and rather short l)odies. The tiftli and sixth 

 show the change to' the middle caudal region, 

 ill wliich tlie zygapophyses are simplified, the 

 arches reduced, the centra increased in length 

 and diminished in width, the transverse pro- 

 cesses shortened and expanded antero-poste- 

 riorly into flat plates as long as the centra, 

 and decreasing in width on each successive 

 vertebra until on the seventeenth they are 

 reduced to ridges on the sides of the centra. 

 The neural arches are complete as far back 

 as the thirteenth vertebra. 



CknnparUons ir'dh IJyivnodon. — In the 

 characters of the vertebral column Si/wpa 

 is nearer to Dap/m'nus and Cynodictls than 

 to Ilyienodon or Patr'iofelis. It agrees with 

 the two former in the large long lumbars, the general character of 

 the spines and transverse processes of most of the vertebrae, propor- 

 tions of sacrum, proximal caudal spines, etc. 



Ihjirnodoti diifers in the superior and inferior hmiina^ of the trans- 

 verse process'es. distinct on cervicals 4—6; the hun1)ars smaller and 

 shorter, their spines broader but not so high, their transverse processes 

 much shorter, the sacrum much smaller, the tail much shorter, and 

 lateral plates of middle caudals not prominent. All these features 

 are probably due to adaptation to running, and are exactly paralled 

 in the distinctions between the modern Canidjv and Dapha-nus or 

 th/nodictis. 



Putriofi'Voi has shorter cervicals than Sbupa, luinl)ars large but short, 

 their zygapophyses revolute, spines broader and wider at top, trans- 

 verse processes short and stout. The sacrum is not so ])road anteriorly, 

 the caudals are massive, but not so long; the anterior ones have 

 extremely broad, massive, transverse processes, while in the middle 

 caudals the transverse lamelhe are reduced to short, stout anterior and 

 posterior processes. The neural arch continues only to the ninth 

 vertebra, a remarkable feature considering the length and power of 

 the tail. 



0.fya!)ia is proportioned much more like Si/iojja, with similar type 

 of dorsals, long and large lumbars, etc., but the skeleton is not com- 

 plete enough to compare exacth\ 



