64 FreLp CoLumMBiAN MuseuM—GEo_ocy, VoL. II. 
pophyses, to the sixteenth dorsal, scarcely differ in their shape and 
relations to the centrum. These vertebrae may, therefore, be properly 
called thoracic. From the seventeenth vertebra to the last one 
preserved, the twenty-second post-cervical, the diapophyses decrease 
rapidly in size, the last being scarcely more than half the length of 
the fourth or fifth. In these posterior processes the proximal articu- 
lation of the arch is as broad as in any of the others, but the distal 
end of the process is more compressed, with only a small surface for 
the small presacral ribs. Over the twentieth vertebra the matrix has 
been cleared away sufficiently to disclose a posterior zygapophysis. 
The free diapophysis in this vertebra is about fifty millimeters in 
length, thirty in height, and about twenty in width. The posterior 
zygapophysis arches upward and backward from the base of the free 









process. 
MEASUREMENTS. 
Length of Centrum. | Widthof Centrum.} Length of Rib. 
Atlanto-axis, . ; go mm. 
Third cervical, ; 46 
Fourth, cervical, . ; erie 82 mm. 60 mm. 
Fifth cervical, 44 
Sixth cervical, . 45 
Seventh cervical, . ; 47 
Eighth cervical, . At 50 84 74 
Ninth ;cérvicalin, 7”. 50 
Tenth cervical, 50 
Eleventh cervical, eee 53 94 
Twelfth cervical, . Grek 
Thirteenth cervical, 60 . 220 
First dorsal, . 64 85 « 260 
Second dorsal, : Bi 68 370 
Third dorsal, ; wa 400 
Fourth dorsal, ; 74 490 
Fifth dorsal, . 77 445 
Seventh dorsal, . i. ar B25 370 
Twelfth dorsal, . ; al 77 82 370 
Twenty-second, . 74 82 
LENGTH OF DIAPOPHYSES. 
Pirsticoe, . + 47 Tam, + Kourth ae ., 90 mm. | Eighteenth) 9 7cem 
Decong fs i OSous Fifth, ; Soe eae Twentieth, SG ta 
Thirds sae bares ebie tg Thirteenth, eo 'OO. 3. Twenty-second, 60 “ 
<> ee 
