78 VERTEBRATA. 



mostly Pliosaurus and Ichthyosaurus, which are the most common 

 and conspicuous fossils of the Kimmeridge and Oxford clays, are 

 absent from the Upware and Brickhill deposits 1 . 



Deinosauria. 



Of the Deinosaurs two teeth of Iguanodon have been found at 

 Upware, now in the collection of Mr J. F. Walker, of York ; and a 

 well-preserved caudal vertebra (Pelorosaurus ?) is in the Wood- 

 wardian Museum (vil. i, Seeley, Catalogue of Reptilia, &c, Cam- 

 bridge, p. 78). None have occurred at Brickhill. 



The figure (Plate I. fig. 1) represents a small claw-like dermal 

 spine of a Deinosaur from Upware, also in Mr Walker's collection. 



An Iguanodon tooth, with its serrated edges perfectly pre- 

 served, has been found by Mr C. J. A. Meyer, F.G.S., in the 

 Bargate stone at Guildford ; and the Cambridge University Museum 

 possesses a fine series of them, usually more or less worn, from 

 Potton. 



Saurians. Plesiosaurus. 



Some of the Plesiosaurian remains from Upware are recorded 

 by Professor Seeley in his Catalogue (Reptilia, &c. p. 75 et seq.), 

 namely v. ^, which he states " indicates a species different from 

 all the Potton forms" ; and v. |, which is the cervical vertebra of " a 

 well marked species." The centrum is very transverse (length 

 1 1 in., breadth If in., depth 1 in.) ; the articular faces are shallow 

 (not deeply concave), with a slight central prominence, and the 

 neural arch is slender, v. ■§ and v. ~ are dorsal vertebras, the 

 former approaching the P. Neocomiensis of Campiche in form. 

 (See PI. I. figs 2, 2a.) Other vertebras are arranged in shelf d, and 

 specimens of the paddle-bones — humerus and femur — are in v. e. 



Besides these there is a set of five vertebras, mid-dorsal and 

 late dorsal in position, well characterized and in unusually good 

 preservation. The centrum is short-cylindrical, the sides and 

 articular faces nearly straight, but slightly concave. Length 35 mm., 

 breadth 38mm., depth 35 mm. 



1 These large vertebrae are found in the Potton bed, and it is important to ob- 

 serve that they occur there in a highly phosphatised condition and with masses of 

 phosphate adhering to them; quite different from the ordinary bones of the 

 Iguanodonts, &c. 



