400 STEUCTURE AND CLASSIFICATION OF BIRDS 



occipital and the basitemporals, is a hollowed area which 

 suggests the impress of the potter's thumb. The thumb of 

 the writer exactly fills it. 



The symphysis of the lower jaws is of unusually limited 

 extent.' 



The vertebral column of Spheniscus Humholdti consists 

 of twenty-one vertebrge in front of the sacrum, of which 

 fifteen are cervical. The atlas is notched for the odontoid 

 process. The catapophyses do not form a canal ; hypapo- 

 physes commence on the eleventh cervical and continue to 

 the last dorsal but one ; they are large on the twelfth and 

 thirteenth ; on the fourteenth they have greatly diminished, 

 but there are two large lateral catapophyses which on C15 

 form two large flanges (as in the diver) ; these arise from 

 one base or Dl, and gradually diminish into a single median 

 hypapophysis again. The first dorsal is the first vertebra 

 to be opisthocoelous, but it is heterocoelous in front. The 

 opisthocoelous characters of the dorsal vertebrae of the 

 penguins are better marked than in other recent birds in 

 which the same structure of vertebra occurs (cf. p. 111). 

 In CEdicnemus, for example, some of the dorsal vertebrae are 

 opisthocoelous, but the convexity in front is by no means so 

 clear as in the penguins. 



The scapula is remarkable for its great breadth posteriorly, 

 which narrows towards the neck. In Pygosceles it is wider 

 actually as well as relatively than in Spheniscus, and has a 

 truncated extremity ; the same is the case with Eudyptes 

 and Aptenodytes. 



The coracoid also shows some differences. In Spheniscus 

 the procoracoid fuses below with the coracoid, leaving an 

 oval foramen about half an inch long ; at the sternal end of 

 the bone is a short upwardly directed snag of bone. In 

 Pygosceles the procoracoid is not fused with the coracoid, 

 but it is carried on by ligament to the snag at the base of 

 the coracoid — as probably also in Spheniscus. The acro- 



' Menzbier des.cribes the quadrate as single-headed. This is not accepted 



by FiJKBKINGEB, 



