356 PROF. ST. GEORGE MIVART ON THE 



rather more distinct, though still small, and the hyperapophyses are decidedly more 

 marked than in the fifth vertebra. 



The SEVENTH VERTEBRA (Plate LVIII. figs. 15-17) is, again, a trifle shorter, but little 

 exceeding the axis in length. Compared with the last vertebra, the styloid processes 

 are yet shorter, and (as in that vertebra) project but very little from the side of the 

 centrum, and are separated fi-om the adjacent catapophysial ridges by a wider, though 

 somewhat shorter, antero-posterior groove. The neural spine is higher; the hypera- 

 pophyses and the metapophyses are stronger ; and the postzygapophyses almost look 

 a little preaxiad as well as ventrad, and a little externad. As in the sixth vertebra, 

 so here the plane of the styloid processes was more dorsad than that of the hinder 

 part of the centrum's ventral surface. The centrum being a little bent on itself 

 from before backwards, its ventral margin (when viewed laterally) is a little concave 

 ventrad. 



A narrow fissure runs preaxiad from the middle of the postaxial margin of the neural 

 arch ; and on each side of this, between it and the adjacent hyperapophysis, is an antero- 

 posteriorly directed groove. 



The EIGHTH VERTEBRA (Plate LVIII. figs. 18-22) agrees with that of Phalacrocorax, 

 and differs from that of Sula and Pelecanus, in that it articulates with its predecessor 

 at an angle open ventrad, as in the more anterior vertebra, while with its successor it 

 articulates at an angle open distad ; but it presents characters altogether peculiar. As 

 in the seventh of Pelecanus and the eighth of Phalacrocorax, the neural spine is more 

 preaxially situated than in its serial predecessor (projecting from about the antero- 

 posterior middle of the neural arch) ; and, as in the seventh of Sida and eighth of Pha- 

 lacrocorax, the styloid processes diverge ventrad from the centrum as they proceed post- 

 axiad. Unlike, however, all the three before-described genera, these styloid processes 

 are enormously long, extending more postaxiad than any other part of the vertebra, 

 and reposing upon the sides of the hsemal arch of the ninth vertebra. The postzygapo- 

 physes also do not project postaxiad as much as does the centrum; and their articular 

 surfaces (which are elongated) look more directly externad than even in Phalacrocorax — 

 though, as in that genus, they differ from those of the sixth vertebra by quite extending 

 to the postaxial ends of those processes. The preaxial part of the neural arch is not 

 pressed back postaxiad ; but the postaxial part of that arch rises dorsad — instead of being 

 curved over ventrad very markedly, as it is in the seventh vertebra; also the postaxial 

 margin of the neural arch, seen dorsally, is more concave than in the preceding vertebra, 

 and without any narrow median cleft. The pra^zygapophyses still extend decidedly pre- 

 axiad of the centrum. The long styloid processes cannot well be determined as more 

 catapophysial or parapophysial ; for they arise from the same part as the parapophysis 

 arises from in the seventh vertebra, while they are continuous dorsally with the preaxial 

 part of the marked catapophysial ridges, which bound laterally the median subcentral 

 , groove ; these latter ridges are externally concave dorso-veutrally, this concavity being 



