STEGANOPODES 



406 



Sula and Pelecamis a slender tendon, running from the arm- 

 pit and ending in unstriated (Sula) or striated (Pelecanus) 

 fibres for the movement of the secondary feathers, was dis- 

 covered. 



The biceps is two-headed in the Steganopodes ; but the 

 arrangement differs from what is common among birds. 

 Both heads, in fact, arise from the coracoid, but the outer 

 one, which corresponds to the humeral head of other birds, is 

 also attached to the humerus. The two muscular bellies are 

 separate in Pelecanus and Fregata, and their tendons unite 



Cor. 



Fig. 190. — Okigin oe Biceps in Pelecanus (Lett-hand 

 Figube) AMD Phalacrocorax (aetek FCbbbingeb). 



Cor, coracoid ; C, coracoidal head of biceps ; A, attachment of humeral head ; 

 B, its prolongation to coracoid. 



to divide again directly. In Fregata, indeed, the division of 

 the tendon of the coracoidal head takes place before the 

 junction. In Phalacrocorax africanus 1 found the coracoid 

 head alone, and it had but one insertion. In Phaeton and 

 Phalacrocorax and Sula the tendons of origin of the two 

 heads from the coracoid are continuous. In Phalacrocorax 

 and Plotus, at any rate, the anconceus has a humeral head. 



The muscles of the leg vary greatly among the Stegano- 

 podes. The following are the formulae for the different 

 genera ; — 



Phaeton AXY — ' Pelecanus AX — 



Plotus AX + Sula AX + Fregata A + . 



Phalacrocorax \ . y 



' Perhaps the ambiens varies. Gabeod, Fobbes, and I did not find it. 

 Ft'EBBiNGER marks it as present, as does Gadow. 



^ ABX P. carho ? AX P. lugubris, P. brasiliensis. 



