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FOSSIL REPTILIA OF THE 



and thickness of the proximal end, and the free termination of the process is more 

 definitely marked by a smooth and shallow groove, over which it seems that the tendon 

 of the " extensor ala3 " may have glided before its insertion into the strong rough 

 process (<?). 



The second phalanx of the wing-finger (Plate I, fig. 28) may have belonged to a 

 Pterodactyle of the same species or size as the proximal phalanx of the Pterodadylus 

 Kiddii. On this hypothesis its proportion of length would resemble that in the Ptero- 

 dadylus {Dimorphodon) macronyx (' Monograph on the Fossil Reptilia of the Liassic For- 

 mations,' Pterosauria, Palaeontological volume for year 1869, Plate XX). The distal end 

 of the present " Stonesfield " bone becomes triedral by the rise of a ridge from the thenal 

 aspect, extending longitudinally, and enlarging, to near the outer end of the distal 

 oblong articular surface ; this is more convex transversely than is the proximal surface, 

 The longitudinal ridge in question afforded insertion to a strong flexor tendon. 



§ 5. Pterosauria from the Lias. 



I have not yet received any evidence of a Pterosaurian from the " Alum Shales " of 

 Whitby, or any other member of the Upper Lias of our North-Eastern Coast, which 

 represents, by the sum of its palaeontological evidence, the " Posidonomyen-Schiefer " of 

 Bavaria. There, however, in the locality of Banz, have been discovered instructive 

 remains of a Pterosaurian, which Professor Quensted refers to my Lower-Liassic genus 

 under the name of Dimorphodon Banthensis. 



The specimen about to be described, from the Lower Lias of Lyme Regis, is 

 insufficient to give subgeneric characters, and is provisionally registered under the wider 

 generic name. 



A. — Pterodadylus Marderi, Owen (Plate I, figs. 7, 8, 9). 



Of this species is here figured the upper or proximal half of the right humerus 

 (figs. 7 and 8). The head or articular surface (fig. 9) is a narrow, bent, or reniform 

 convexity, with the concave margin toward the thenal side of the bone (fig. 7). The 

 inner and more obtuse end of the articulation, with the tuberosity of that side, is broken 

 away ; the outer, narrower, and, in this species, pointed end is lost upon the ridge or 

 upper border of the "pectoral process" {b). The expanded part of the shaft, beyond 

 the articulation, is concave transversely on the thenal aspect (fig. 7), convex on the 

 opposite or anconal side (fig. 8), which shows, as usual, no trace of the fossa and foramen 

 characterising that part of the humerus in Birds of flight. The antero-posterior thickness 



