AXIAL SKELETON OF THE PELECANID^E. 347 



seventh vertebra, though the hyperapophyses have come to join and diverge from the 

 neural spines. Thus this vertebra is like the seventh ofPelecanus. Sula is intermediate, 

 since in it the seventh vertebra does not bifurcate postaxially, as in Pelecanus, yet the 

 preaxial part of the eighth is more pressed back than that of the seventh of Pelecanus^ 

 and less so than that of its eighth vertebra. 



The postzygapophyses look more externad than either in Pelecanus or Sula. 



The styloid processes are much larger than in the seventh vertebra. 

 . In the eighth vertebra the styloid process has come to start rather from the middle 

 than from the external border of the groove on each side of the preaxial part of the 

 median subcentral groove. It has thus become rather catapophysial than parapo- 

 physial, and the same change has taken place here as has been described as occurring 

 in the corresponding vertebra of Sula. 



The NINTH VERTEBRA (Plate LVIL figs. 17-20) is, like the ninth of Sula, elongated; 

 but the neural spine is smaller, and the prsezygapophyses look more mesiad. It evidently 

 corresponds with the eighth of Pelecanus, though there is no haemal arch, it being the 

 first one in which the preaxial part of the vertebra is pressed in postaxiad, with a trans- 

 verse constriction behind the praezygapophyses. The three tubercles outside the pleura- 

 pophysial lamella are distinctly developed, with the parapophysial projection below them, 

 as in Sula. The rib-like styloid processes are larger and more slender than in the eighth 

 vertebra, and much more so than in the ninth vertebra of Sula. 



The TENTH VERTEBRA (Plate LVIL figs. 21-23) is, like the tenth of Sula, somewhat 

 drawn out ; but there is no haemal arch 1 . In this and the preceding vertebra in Sula 

 the rib-like styloid process is antero-posteriorly grooved on its ventral surface not so in 

 Phalacrocorax. 



The ELEVENTH, TWELFTH (Plate LVIL fig. 24), and THIRTEENTH VERTEBRAE are, like 

 those of Sula, somewhat lengthened ; but in none is the hremal arch completely closed 

 ventrally. In the eleventh vertebra the postzygapophyses fail, for the first time, to attain 

 the postaxial limit of the centrum. In the last of these vertebra? the styloid rib-like 

 process reverts to its condition in the seventh vertebra, inasmuch as it here again extends 

 from the external margin of the lateral antero-posterior subcentral groove; i. e. it is again 

 rather parapophysial ; and the parapophysial projection, distinct in the ninth, tenth, 

 and eleventh vertebras, has here coalesced with the root of the rib-like process. 



The FOURTEENTH VERTEBRA is substantially like that of Sula's fourteenth vertebra ; 

 but when viewed dorsally it is more constricted laterally, the prsezygapophyses look more 

 directly mediad ; the neural spine is more developed, ending in a sharp dorsad and 

 postaxiad process at its postaxial end. Viewed laterally, a large, median, laterally 

 compressed bypapophysis here appears suddenly for the first time, largely perforated 



do so already in the sixth vertebra. In all three genera the processes begin again to project postaxiad of the 

 articular surface in the fifteenth or sixteenth vertebra. 



1 The styloid ribs are excessively long in this and adjacent vertebrae of 1182 c in the College of Surgeons. 



VOL. x. PART vii. No. 5. August 1st, 1878. 3 B 



