530 ^Ii-. E- W.IIooley on the 



<rem\s Ornithocheirus " no teeth anterior to palate '' ; but, 

 becoming " convinced " that the type of Pterodactylus simus 

 was a lower jaw, Seeley abandoned the genus Ptenodactylus, 

 and included all the specimens under Ornithocheirus, being 

 thus compelled to add the character " the teeth are pro- 

 longed anterior to the muzzle/' nullifying the original cha- 

 racter of the genus. 



Further characters appear to have been added after the 

 discovery of the toothless forms of America, when "it 

 became evident that the bones of the skeleton are mostly 

 formed on the same plan as those of the Cambridge genus 

 Ornithocheirus." The foundation for this seems to be that 

 portions of an edentulous jaw had been found in the Cam- 

 l)ridge Greensand. These were determined by Owen^ to be 

 the " proximal end of metacarpal of wing,'' and recognized 

 later by Seeley t as parts of the premaxillse. In 1891 J he 

 refers to his provisional name of Ornithostoma for these 

 three portions of edentulous jaws, details the resemblances 

 to Pteranodon, and finds the only difference is " the American 

 toothless Ornithosaur is twice the size." Then follows the 

 inclusion of characters belonging to Pteranodon into both 

 Ornithocheirus and Ornithostoma. The odd fragmentary 

 bones show the same characters as the American forms, and 

 these are made common both to the toothed and toothless. 

 In regard to the beak, the following description reveals the 

 confused state of things § : — " The beak varies greatly in 

 length and in form, though it is never quite so pointed as in 

 the American genus, for there is always a little truncation in 

 front, when teeth are seen projecting forward from a position 

 somewhat above the palate ; the snout is often massive and 

 som.etimes club-shaped." In regard to the toothless jaw 

 [Ornithostoma)^ it not only diverges from the original and 

 the amended characters laid down for Ornitliocheirus in the 

 absence of teeth, but also "in the smooth palate formed by 

 a single wide concave channel," whicli is widely at variance 

 with the well-developed lougitiuliiial ridge of the palate in 

 the latter. Seeley saw evidence of the crest on specimen 

 no. J. c. 8, 2, a fragment of the back of the skull which he 

 described and figured || in 1870. Twenty-one years later he 

 still held to this, but uas apparently shaken in his deter- 



* IJ. Owen, Rep. Cret. Form. (Mon, Pal. Soc. 1859), Suppl. i. p. 18. 

 t II. G. Seeley, Ann. iS: Mag. Nat. Hist. (4) vol. vii. p. y.5, footnote 

 (}871). 



X 1(1. ibid. (0) vol. vii. p. \\\ (1801). 

 § Id. ' Dragons of tlm .\ir,' 1(»01, p. 177. 

 II Id. ' Oniithosauria,' 1870, pi. xi. tig. 1, 



