12 ICHTHYOPTERTGIA. 



48000. Eight associated bones of the pectoral limb ; from the 

 Oxford Clay, near Oxford. These specimens comprise the 

 radius and ulna and five other bones. The radius and 

 ulna closely resemble those of the type specimen, but are 

 rather smaller. Presented by the Hon. B. Mar sham, 1877. 



R. 472. A right femur, probably belonging to this species • from 

 the Oxford Clay of Stanground, near Peterborough. The 

 contour of the proximal portion is of the type of the cor- 

 responding bone of Ichthyosaurus campylodon. The facet 

 for the homologue of the pisiform is broken away *. 



Presented by Sir B. Owen, K.C.B., 1884. 



Ophthalmosaurus (?), sp. 



The following specimen, which is provisionally referred to the 

 present genus, indicates an individual of much larger size than 

 either of the above-mentioned Cretaceous specimens. 



Hab. Europe (England). 



R. 1192. The imperfect right dentary bone of a very large Ichthyo- 

 pterygian ; from the Upper Green sand of Warminster, 

 Wiltshire. A series of small dental alveoli are seen at 

 the anterior extremity, but there are none posteriorly, 

 although there is a dental groove ; the specimen therefore 

 accords with Baur's description of the jaw of Ophthalmo- 

 saurus. No history. 



Genus ICHTHYOSAURUS, Conybeare {ex Konig 2 , MS.). 



Syn. Proteosaurus, Home 3 . 

 Gryphus, Wagler 4 . 



Teeth generally large and extending throughout the jaws. 

 Humerus (fig. 9) and femur with or without strongly-marked tro- 

 chanteric ridge : and normally with two distal facets for the re- 

 spective articulation of the short radius and ulna and tibia and 

 fibula, which bones are respectively in close apposition to one 

 another, and are of more or less quadrangular outline, the radius 

 being either transversely elongated or nearly square. Clavicles 

 mesially united by anchylosis or squamous overlap, with the trans- 

 verse portion of the interclavicle resting upon the ventral aspect. 



1 See p. 5. 



2 Trans. Geol. Soc. ser. 1, vol. v. pt. 2, p. 563 (1821). 



3 Phil. Trans. 1819, p. 212.— This name has the priority ; see Introduction. 



4 Syst. Amphib. p. 60 (1830). 



