1897.] AlfATOMT OF PHAETHOTf. 291 



The Sartorius, as already mentioned, just overlaps tbe latissimus 

 dorsi posterior. 



The Glutceus primus is not a large muscle ; its origin does not 

 extend back behind the acetabulum. 



The Biceps is continuous at its origin with the semimembranosus. 

 As Garrod has poinied out, it is remarkable for the absence of 

 a Biceps sling — a peculiarity which it shares with certain Swifts. 



As Garrod has also pointed out, the muscular formula of the leg 

 is AXY— \ 



The deep Flexors blend at the middle of the metatarsus ; no slip 

 is given off to the hallux, which has a short flexor of its own. 



The osteology of Phaethon has been described and figured as 

 concerns the skull and a few other booes by Brandt -. Two species, 

 P. candidus and P. rubricauda, are dealt wifh by ]\Iihie-Edwards '. 

 Some notes upon the axial skeleton are contained iuMivart's^ 

 account of that portion of the skeleton of the Pelecanidse. 



Gadow " has referred to the less modified condition of the palate 

 in Phaethon. This is certainly the case, but Fregata is not far 

 removed from Phaethon. 



In Phaethon (fig. 3, p. 292) the palatines are narrowed 

 posteriorly and come into contact for a short space in the middle 

 line, where, however, they are not fused. The vomer is knife-blade 

 shaped and ends in a point anteriorly between the maxillo-palatines; 

 it splits into two posterior limbs just behind the maxillo-palatines. 



In Fregata (fig. 4, p. 293) the two palatines not only come into 

 contact, but are actually fused for about the same distance 

 posteriorly ; but the internal laminae of the palatines remain distinct 

 and are not melted into a median ridge as is the case with the 

 remaining genera of Steganopodes, where, moreover, the palatines 

 are, as is well known, much more largely fused. 



In both Phaethon and Fregata the maxillo-palatines do not meet 

 across the middle line posteriorly, the appearance of this part of the 

 skull being very Accipitriue. I have already referred to the vomer of 

 Phaethon ; in Fregata this bone lies more deeply (when the skull is 

 viewed from below), but does not bifurcate posteriorly where it is 

 ankylosed, as in Phaethon, with the palatines. In Phalacrocorax, 

 Plotus, and Sula the backwardly projecting, horizontal and separated 

 laminae of the maxillo-palatines are absent and it seems to be doubtful 

 whether there is any vomer. 



Pelecanuscoxaes nearest in this particular to Fregata and Phaethon, 

 but the regions of the maxiUo-palatiues in question are united 

 across the middle line by help of a distinct septum, which may be 

 at least partly the anterior portion of the vomer. 



' Fiirbringer in the table of characters marks the ambiens of Phaethon as 

 present. I take it that this is )iierely a misprint. 



^ " Beitrage zur Keinituiss cler Naturg. der Vcigel," Mem. Ac. Sci. St. Peters- 

 bourg, (6) iii. p. 81. 



^ Histoire Naturelle de Madagascar. 



* "On the Axial Skeleton of the Pelecanidte," Trans. Zool. Soc. x. p. 315. 



' Aves, in Bronn's ' Thierreich,' Syst. Th. p. 101. 



