22 ICHTHTOPTEKTGIA. 



Ichthyosaurus indicus, Lydekker 1 . 



Known only by a few vertebral centra ; probably closely allied 

 to, if not identical with, the preceding species. 

 Hah. India (Madras). 



R. 307. An imperfect vertebral centrum of a large individual, pro- 

 visionally referred to this species ; from the Upper Cre- 

 taceous of Madras. This specimen has been much injured 

 by weathering, and one surface has been cut and polished. 



By exchange. 



Ichthyosaurus trigonus, Owen 2 . 



Syn. (?) Ichthyosaurus posthumus, Wagner 3 . 

 (?) Ichthyosaurus cuvieri, Valenciennes 4 . 

 (?) Ichthyosaurus normannice, Valenciennes 5 . 



Of very large dimensions, but imperfectly known. Teeth of the 

 Campylodont type, the undermentioned specimens having their 

 crowns more conical and the flutings of the enamel finer than in 

 /. campylodon. Centra of vertebrae comparatively long, with the 

 cupping of the terminal faces very deep, and in the cervical region 

 occupying the whole of these faces. In the dorsals the centra are 

 of moderate breadth ; the vertical diameter in the middle part of the 

 series not exceeding the transverse. 



This species was founded upon vertebrae from the Kimeridge Clay, 

 which are not now forthcoming ; and it will be convenient- to 

 regard those figured by Phillips in his ' Geology of Oxford ' as re- 

 presenting the types. /. cuvieri was founded upon a skull from 

 the Kimeridgian of Boulogne, having teeth of the Campylodont type, 

 which is figured by Lennier in his ' Etudes geologiques et paleonto- 

 logiques sur l'Embrasure de la Seine' (Havre, 1870), pi. vi. ; while 

 /. normannice was based on a basioccipital, basisphenoid, and vertebrae, 

 obtained at the same time from the same spot, and figured by 

 Lennier in the plate cited. As stated by that writer, it is almost 

 certain that all these remains belonged to the same individual; and 

 it is probable that the species in question is identical with /. 

 trigonus. 



There is no decisive evidence that this species belongs to Ichthyo- 



1 Palseontologia Indica (Mem. Geol. Surv. Ind.), ser. 4, vol. i. pt. 3, p. 28 

 (1879). 



2 Kep. Brit. Assoc, for 1839, p. 124 (1840). 



3 Abb. k. bay. Ak. Wiss. vol. vi. pt. 2, p. 702 (1851). 



4 Comptes Eendus, vol. liii. p. 273 (18( ; 1). 



5 Ibid. p. 1001. 



