CRETACEOUS PTERODACTYLES. 383 



laniariforin teeth — we may assign a length of 2 inches 8 hnes to the teeth implanted in 

 the part of the upper jaw here described. The interspace between the two sockets is 3| 

 hnes, or half that of the long diameter of the socket ; the plane of the opening of the 

 socket, and the interspace, present the same obliquity as they do in Pterodactylus 

 Sedywickii (tig. 1 ) ; and as the proportion of the interspace to the socket is also the 

 same, the present fragment has most probably belonged to a larger individual of the same 

 species. Since the outer border of the sockets does not swell out beyond the outer 

 wall of the jaw, the fragment has been part of jaw behind the anterior swelling caused 

 by tlie proportionally large prehensile teeth ; and as, from the analogy of known 

 Pterodactyles, the teeth succeeding those anterior ones are not of larger size, but are 

 usually smaller, at any posterior part of the jaw, we may, therefore, with due 

 moderation, frame an idea of the Pterodactyle to which the maxillary fragment (fig. 6) 

 belonged, as surpassing in size that to which the portion of jaw (fig. 1) belonged, in 

 the proportion in which the socket in fig. 6, a, exceeds the last socket in fig. 1, b. 

 Such an idea impels to a close scrutiny of every character or indication of the true 

 generic relation of the present fragment in the Reptilian class ; but the evidence of the 

 large and obviously pneuniatic vacuities, now filled by the matrix, and the demon- 

 strable thin layer of compact bone forming their outer wall, permit no reasonable 

 doubt as to the pterosaurian nature of this most remarkable and suggestive fossil. 

 All other parts of the Flying Reptile being in proportion, it must have appeared, with 

 outstretched pinions, like the soaring Roc of Arabian romance, but with the demo- 

 niacal features of the leathern wings with crooked claws, and of the gaping mouth 

 with threatening teeth, superinduced. 



The last portion of jaw of a Pterodactyle from the Cambridge Green-sand which 

 will here be described, is that figured in PI. 7, fig. 7, a, 6, c, d. It is part of the 

 lower jaw, and indicates a smaller individual of Pterodactylus Sedgwickii than the 

 specimens, figs. I and 2. In a longitudinal extent of 2| inches, six successive sockets 

 are shown, but with only the two middle pairs perfect. Their orifices have the same 

 obhquity as in fig. 2 ; and the surface of the bone between the right and left sockets 

 shows the same median longitudinal groove. Opposite the middle sockets the sides 

 of the jaw are preserved nearly to the median inferior ridge, as shown in fig. 7, c; 

 these sides being flat and straight, and giving the transverse section shown at fig. 7, d. 

 The intervals of the sockets are a little wider, proportionally, than in some of those in 

 fig. 2, but not more than a hinder position in the jaw would account for, without 

 having recourse to a distinction of species to explain it. 



Two species, however, are satisfactorily established, both of them distinct from any 

 of the known large Pterodactyles of the Chalk, by the portions of jaws from the Upper 

 Green-sand near Cambridge, viz., Pterodactylus Sedgwickii, with more approxi- 

 mated alveoli (PI. 7, figs. 1 and 2, witli probably 6 and 7) ; and Pterodactylus 

 Fitfoni (ib., figs. 3, 4. and 5). 



