2 FOSSIL REPTILIA OF THE 



Pterod-actylus simus, Owen. 



Jaws and teeth (Tab. I, figs. 1 — 10). 



The first evidence I have to offer of this truly gigantic flying reptile consists 

 of the corresponding part of the upper jaw with that on which the Pterodactylus 

 SedgwicMi was founded, viz., the anterior extremity forming the muzzle (Tab. I, 

 figs. 1 — 5), including the first four (a, b, c, d) and part of the fifth ( e ) sockets of the 

 teeth. The comparison and appreciation of the specific distinctions of the two 

 large Pterodactyles are thus rendered easy and satisfactory. 



In the specimen of Pterodactylus simus (Tab. I, figs. 1 — 5), the first tooth (a) on 

 the left side remains in the socket ; it is not larger than the corresponding tooth 

 in Pterodactylus SedgwicMi, and, consequently, is relatively much smaller than in 

 that species. Its socket and that of its fellow, moreover, are differently situated, 

 opening downwards, like the succeeding sockets, and the position of the exserted 

 foremost tooth is accordingly vertical and nearly parallel with the lower half of 

 the anterior contour of the muzzle. In Pterodactylus SedgwicMi, the sockets of 

 the first pair of teeth open upon the forepart of the muzzle, and look almost 

 directly forward,* and their teeth had, consequently, a nearly similar direction ; 

 the same, viz., which they appear to have had in Pterodactylus suevicus, Qnst.f 



The contour of the muzzle in Pterodactylus SedgivicJcii rises at first vertically 

 above these sockets before curving back into the upper part of the skull's profile, 

 and gives an obtuse anterior termination to the upper jaw ;t but this character is 

 much exaggerated in the present specimen (Tab. I, figs. 1 and 3), not only by the 

 greater relative extent of the vertical part above the front sockets, but by the 

 greater breadth of that part, which is flattened anteriorly, forming a surface (fig. 3) 

 of nearly 2 inches in length, about 10 lines in breadth below, and contracting 

 gradually above to a point, where the blunt ridge begins that forms the upper 

 part of the profile of this portion of the skull. The name proposed for the 

 species refers to this peculiarly obtuse and flattened forepart of the cranium. 

 In Pterodactylus SedgwicMi, the upper ridge of the forepart of the cranium 

 is continued down to between the first pair of sockets,§ the muzzle being only 

 obtuse vertically, and not transversely, as in Pterodactylus simus. 



The flattened anterior surface, in the specimen figured (Tab. I, fig. 3), is im- 



* 'Monograph' for 1857, tab. i, fig 1, c. 



t ' Ueber Pterodactylus suevicus,' &c, 4to, 1855, fab. i. 



% 'Monograph' for 1857, p. 2, tab. i, fig. 1. 



§ lb., tab. i, fig. 2. 



