Zoological Society. 387 



The extremity of the upper jaw of the Pterodactyhis Cuvieri is 

 sufficiently perfect to demonstrate that it had a pair of approximated 

 alveoh close to its termination, and we may therefore refer it to the 

 Dontirostral division. 



In this division, however, there are species which present such dif- 

 iVrent proportions of the heak, accompanied hy differences in the rela- 

 tive extent of the dental series, as would without douht lead to their 

 ■llocation in distinct genera, were they the living or recent subjects 



the modern Erpetologist. In the Pterodactyhis lotiffirostris, the 

 i rst species discovered and made known by CoUini in 1 784 *, the 

 j uvs are of extreme length and tenuity, and the alveoli of the upper 

 jaw do not extend so far back as the nostril. In the Pterodactylus 

 crassirostris, Goldfuss f, on the other hand, the jaws are short, thick, 

 and obtusely terminated, and the alveoli of the upper jaw reach as 

 far back as the middle of the vacuity which intervenes between the 

 nostril and the orbit, and which Goldfuss terms the ' cavitas inter- 

 media.' 



In the solid or imperforate part of the upper jaw anterior to the 

 nostril, t\\G Pterodactyhis longb'ostris has twelve long, subcomprcssed 

 teeth, followed by a few of smaller size : the same part of the jaw 

 in the Pt. crassh-ostris has but six teeth, of which the first four are 

 close together at the end of the jaw, and the first three shorter than 

 the rest. The cavitas intermedia mPt. longirostris is much smaller 

 than the nostril ; in the Pt. crassirostris it is larger than the nostril. 

 Were these two species of dentirostral Pterosauria to be taken, as 

 by the modern Erpetologist they assuredly would, to be types of two 

 distinct genera, the name Pterodactylus shovdd be retained for the 

 longirostral species, as including the first-discovered specimen and 

 type of the genus ; and the crassirostral species should be grouped 

 together under some other generic name. 



The specimen of gigantic Pterodactyle described by Mr. Bower- 

 bank at the last meeting of the Society consists of the solid anterior 

 end, ^. e. of the imperforate continuous bony walls, of a jaw, com- 

 pressed and decreasing in depth, at first rapidly, then more gradually, 

 to an obtusely-pointed extremity. As the symphysis of the lower 

 jaw is long and the original joint obliterated, and its depth somewhat 

 rapidly increases by the development of its lower and back part into 

 a kind of ridge in some smaller Pterodactyles, the present specimen, 

 so far as these characters go, might be referred to the lower jaw, and 

 its relatively inferior depth to the upper jaw in the Pt. comrostris 

 would seem to lead to that conclusion. But the present is plainly a 

 species which has a longer and more slender snout in proportion to its 

 size, and the convex curve formed by the alveolar border, slight as it 

 is, decides it to be part of the upper jaw. The lower jaw, moreover, 

 might be expected, by the analogy of the smaller Pterodactyles, to be 

 flatter or less acute below the end of the symphysis. 



The specimen of Pt. Cuvieri consists of the anterior extremity of 



* Acta Academiae Theodoro-Palatinae, V. p. .58, tab. 5. 



+ Beitrjige zur Kenntniss verschiedencr Reptilicn der Vorwelt, 4to. 1831, sec. 1. 

 tab. 7, 8, 9. 



25* 



