STEGANOPODES 409 



In Phaeton flavirostris the syrinx is typically tracheo- 

 bronchial and not flattened, as in Fregata. 



The skull of. the Steganopodes ! is desmognathous. It is 

 most extremely so in Pelecanus, in correlation, perhaps, with 

 the long broad beak. Pelecanus, in fact, may be described 

 as doubly desmognathous, for the palatines are not merely 

 united but ankylosed behind the posterior nares, which are 

 of limited extent. They form but one bone with a deep 

 ventral median crest, and on the opposite side an equally 

 pronounced dorsal crest, occupying a space left by the here 

 deficient interorbital septum. Fregata is nearly at the 

 other extreme, for the maxillo-pala tines are largely free from 

 each other in the middle line, and the palatines are only 

 united for a short distance posteriorly. Phaeton ' 2 is most 

 like Fregata, but here there is no fusion between the 

 palatines. The strong inferior crest of Pelecanus is repre- 

 sented by two feeble ridges of limited extent. Phalacrocorax 

 is intermediate. The maxillo-palatines are completely united. 

 The palatines are fused for the greater part of their length 

 posteriorly ; they are, however, quite flat above and have below 

 but a faint trace of the median crest. The interpalatine 

 space anteriorly is much more capacious than in Pelecanus. 

 Plotus agrees with Plialacrocorax. 



The Steganopodes are generally (HUXLEY, FURBKINGEE, 

 GADOW) said to have no basipterygoid processes. In 

 Pelecanus rufescens, however, I find a pair of thorn-like 

 outgrowths in the right position (cf. Platalea, p. 439), which 

 I take to be the rudiments of these structures. 



The bony nostrils are holorhinal, pervious only in Phaeton, 

 m others much obliterated by bony growths, as in Herodiones ; 

 in Plotus, indeed, reduced to the merest chinks. As in some 

 Herodiones and Tubinares they are continued forward by a 

 marked groove which runs to, or near to, the very end of 

 the bill, absent only in Phaeton. In Fregata there is no 



1 All the types are described and figured by BRANDT, ' Zur Osteologie di-r 

 Vogel,' Mem. Ak. St. Petersb. 1840 (6), Hi. p. 81. See also for osteology of 

 Plotus and Phaeton MILNE-EDWARDS in Hist. Nat. Madagascar. 



- BEDDARD, ' Notes upon the Anatomy of Phaeton,' P. Z. S. 1897, p. 288. 



