120 MB. C. W. ANDREWS ON REMAINS OE .EPYORNIS [Feb. 6, 



Of the two fairly complete large dorsals the one (Plate XV. 

 figs. 5 & 6) which appears to be the anterior gives the following 



measurements : — 



cm. 



Length of centrum 7*5 



Approximate height from ventral surface to top of 



neural spine 22*0 



Width of centrum in middle 5*0 



Diameter of neural canal from side to side 1*5 



The centrum, which is slightly compressed, is produced ventrally 

 into a haemapophysis, which has been mostly broken away. The 

 anterior articular surface is broader than high, while the reverse 

 is the case in the hinder. The neural arch is very massive, and its 

 sides below and in front of the broken transverse process are 

 excavated by a large fossa roughly pyramidal in form. The 

 articular surface of the anterior zygapophyses is nearly circular, 

 its diameter being about 4*2 cm. ; in the posterior the surface is 

 oval. The neural spine which slopes forward is very large and 

 high ; it is united with the post-zygapophyses and transverse 

 processes by two pairs of thin vertical buttresses of bone, and with 

 the anterior border of the arch by a median unpaired buttress ; 

 between these plates of bone there are deep pyramidal fossa?. The 

 result of this arrangement is that, though the vertebra? are very 

 large, they are at the same time extremely light. The transverse 

 processes and the anterior lateral borders of the centrum being 

 broken away, there is no trace of the articular surface for the 

 ribs. 



The other large dorsal appears to have been posterior to the one 

 just described. Its centrum is less compressed than that of the 

 latter, and, as far as can be seen, there was no haemapophysis. 

 Both the anterior and posterior articular surfaces of the centrum 

 are about as broad as high. The articular surface of the post- 

 zygapophyses are ovoid in shape and of great size, the loug axis of 

 that on the left side measuring 6*7 cm., though in this specimen 

 that on the right side is somewhat smaller. The fossae in the side 

 and on the dorsal surface of the arch are much like those described 

 above, but there is an additional median one between the post- 

 zygapophyses, bounded in front by the neural spine and behind 

 by the hinder border of the neural arch. The dimensions are : — 



cm. 



Length of centrum 7'2 



Width of centrum in middle 6*0 



Height of centrum in middle 6*0 



As in the last specimen the articular facets for the ribs are 

 broken away. 



As was mentioned above, the smaller dorsals closely resemble 

 the larger iu most respects ; they differ, however, in the form of 

 the anterior and posterior articular surfaces of the centrum. 

 These are concave and convex from side to side respectively, as 



