OOLITIC PTERODACTYLES. 547 



affords an oblong, moderately developed, concavo-convex surface for the second phalanx 

 of the wing-finger. 



This bone, from the Stonesficld Oolite, is sHghtlv crushed. 



B. — Pterodaciylus Duncani, Owen (ib., Plate 19, fig. 18). 



The first phalanx of the vifing-finger, referred to the alwve species, is of the left wing, 

 and is imbedded with the anconal surface exposed in a slab of Stonesfield Slate. 



It is from a larger Pterodactyle than the preceding. The extensor process is thicker 

 but springs from a less extended base, relatively to the length of the bone. 



C. — Pterodacti/lus Aclandi, Owen (ib., Plate 19, fig. 19^ 



This species is represented by a still larger specimen of the characteristic wing-bone 

 (fig. 19) in Pterosauria. The olecranoid process (e) is shorter in proportion to the breadth 

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

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

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

 process («"). 



The second phalanx of the wing-finger (Plate 19, fig. 28) may have belonged to a 

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

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

 Pterodaciylus {Dimorphodoii) macronyw {Pterosauria, Plate 17). 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 fiexor tendon. 



§ 5. Pterosauria from the Lias. 



I have not yet received any evidence of a Pterosaurian froui 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 palajontological evidence, the " Posidonomyen-Schiefer " of 

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



