OnONTOPTEEYGIB^. 57 



Family ODONTOPTERYGIDiE. 



The single representative of this family, which is provisionally 

 referred to the Steganopodes, differs from all the existing repre- 

 sentatives of the suborder by the absence of distinct temporal fossae. 

 It resembles these forms, however, in the general contour of the 

 quadrate, which has a broad posterior surface ', with an emarginate 

 external border, and the cup for the head of the quadrat o-jugal 

 placed immediately below this emargination and looking directly 

 outwards. The depressed form of the cranial region also approxi- 

 mates to that of the suborder Steganopodes. The lachrymals like- 

 wise appear to be similar to those of the latter. In the horny 

 covering of the beak being composed of several pieces, Odontopteryx 

 resembles some existing Steganopodes, such as Tachypetes and Sula ; 

 while in Sida the edges of the horny covering of the beak are 

 serrated, although in the reverse direction to the serration of the 

 bones of the fossil form. 



The undermentioned ulna, if rightly referred, is practically con- 

 clusive as to the serial affinity of the genus. 



Genus ODONTOPTERYX, Owen \ 



The cranial part of the skull is vaulted, with a comparatively 

 narrow interorbital bar, a nearly straight profile, an angulated pre- 

 maxiUary region, and a deep mandibular symphysis. 



The margins of the bones of both the upper and lower jaws are 

 coarsely serrated, 



Odontopteryx toliapica, Owen \ 



The iy^e and only known species. Skull considerably larger 

 than that of Sula hassuna. 

 Hah. Europe (England). 



44096. The imperfect skull ; from the London Clay (Lower Eocene) 



(Fig.) of the Isle, of Shcppey, Kent. The type ; described and 



figured by Owen in the ' Quart. Journ. Geol. Soc' vol. 



' lu the Anseres, \yitli which Odcintoptcryx has been compared, the posterior 

 border of the quadrate is narrow, the outer border not emargiuate, the quadrato- 

 jugal cup docs not look directly outwards, and there is a large low tubercle on 

 the posterior surface adjacent to this cup. 



- (^uart. Joui-n. Geol. Soo. vol. xsix. p. 511 (1873). ^ hoc. cit. 



