42 



FOSSIL REPTILIA OF THE 



vertebral column, of the species which he called Pterodadyhis macronijx — the first 

 evidence of the genus from deposits so low, or ancient, in the Oolitic series. 



In 1858 I obtained the skull, with a few other parts of the skeleton of the same or a 

 closely allied species, from the Lower Lias at Lyme Regis, and communicated a brief 

 notice of it to the British Association, which that year met at Leeds.^ 



This specimen confirmed the accuracy of Buckland's conjecture, which I had doubted, 

 viz., that the portion of lower jaw with the series of small lancet-shaped, close-set teeth,^ 

 in a second slab of Lias, belonged to the same Pterodactyle as the limb-bones he described ; 

 but it also showed that these teeth, so like those of some Fishes, were limited to the lower 

 jaw, and were associated, in the same mouth, with long, slender, trenchant and sharp- 

 pointed laniaries, projecting with wide intervals, and set in advance ; which kind of teeth 

 had, hitherto, alone been found in the different species of flying Reptiles. 



The chief result of the study of the second discovery of a Pterosaurian in Lias, viz., 

 its evidence of a new^ generic form {Dimorjjhodon) in the order of volant Beptilia, in 

 addition to Rampliorkynchus, von Meyer, and Pterodactylus proper, was noted in the com- 

 munication above cited. 



The third specimen about to be described confirms that taxonomic deduction, showing 

 a combination of the caudal character, mainly differentiating Mamphorhynclius from 

 Pterodadylm, with the dental character above defined. 



I propose first to describe and figure the two specimens yielding the cranial and 

 dental characters of Bimorpliodon, and then to attempt a restoration of the Liassic species, 

 D. macronyx. 



The first specimen with the skull is figured in PI. XVIL It is on a slab of Lias, mea- 

 suring 11 inches by 7 inches. The right side of the head is exposed :^ it has been subject 

 to pressure and some degree of dislocation. Certain bones of both wings, and a few 

 other parts of the skeleton are preserved, pell-mell, in this slab, pressed amongst 

 and upon the bones of the head, especially at the back part of the skull. 



The right premaxillary (22), maxillary (21); and nasal (15), are almost in their natural 

 positions, give the profile contour of that part of the skull, show most of the teeth of the 

 right side upper jaw, and reveal the singular expansion of the nasal (w) and antorbilal (a) 

 vacuities. The alveolar part of the left maxillary (8'), with its ascending postnarial 

 branch has been pushed obliquely downward, with fracture, but without much 

 displacement, of the beginning of the alveolar ray, the inner surface of which is 

 exposed. 



The mandible (,32) has been dislocated and pushed below the place of its articulation 

 with the tympanic (28) : the left ramus has also been subject to the same force which has 



1 "On a New Genus {Bimorphodon) of Pterosauria, -with Kemarks on the Geological Distribution of 

 Flying Reptiles ;" in 'Reports (Sections) of tlie British Association,' 1858, p. 97- 



2 Buckland, loc. cit., pi. xxvii, fig. 3. 



^ The specimen has been drawn, in PI. XVII, without reversing. 



