36 Reports and Proceedings. 



species of Emys, one species of Testudo, one species of a new genus, 

 Trachjdermochelys, a new Emydian genus, which, had an exterior 

 pustulous ornamentation not unlike Trionyx, and was covered with 

 scutes. The remaining sixteen species of Clielonia belong to a new 

 genus, Bhinochelys, having for its type Chelone pidchriceps (Owen). 

 It is Emydian in its affinities, and well characterised by having the 

 nasal and pre-frontal bones distinct ; by the posterior nares being 

 formed by the maxillary and palatine bones, and divided by the 

 whole length of the vomer, which extends on the palate between the 

 palatine and premaxillary bones ; and by the temporal region being 

 covered by an arrangement of bones like that in Chelone. The total 

 number of species of all these groups obtained from the Cambridge 

 Greensand is seventy. In concluding this brief notice of Mr. 

 Seeley's Index, we must express our satisfaction at the clear manner 

 in which the descriptions of the bones are given, so that the student 

 will find very little difficulty in making use of it, when he compares 

 the specimens arranged in the Museum with any bones which he 

 himself may chance to obtain. We hope that it may be soon followed 

 by the illustrated descriptions of the new genera and species referred 

 to in this work, until the appearance of which it would be premature 

 to pronounce judgment on the many new forms here announced by 

 the author, for the first time by name only. 



Geological Society of London. — I. November 24th, 1869. — The 

 following communications were read :— 1. " On the Dinosauria of 

 the Trias, with observations on the Classification of the Dinosauiia." 

 By Prof. Huxley, LL.D., F.E.S., President. 



The author commenced by referring to the bibliographical history 

 of the Dinosauria, which were first recognized as a distinct group by 

 Hermann von Meyer in 1830. He then indicated the general 

 characters of the group, which he proposed to divide into three 

 families, a^z. . — 



I. The Megalosauridffi, with the genera Teratosaurus, Palccosaurus, 

 Megalosanrus, Poikilopleuron, LaHaps, and probably Eushelosaurus ; 



II. The Scelidosauridas, with the genera Thecodontosaurus Hylce- 

 osaurus, PJiolacantlius, and AcanthopJiolis ; and 



III. The Iguanodontidas, with the genera Cetiosaurus, Igimnodon, 

 Hypsilophodon, Iladrosaurus, and probably Stenopelys. 



GompsognatJius was said to have many points of affinity with the 

 Dinosauria, especially in the ornithic character of its hind limbs, but 

 at the same time to difier from them in several important particulars. 

 Hence the author proposed to regard Compsognatlms as the represen- 

 tative of a group (Comp)sognatha) equivalent to the true Dinosauria, 

 and forming, with them, an order to which he gave the name of 

 Ornithoscelida. 



The author then treated of the relations of the Ornithoscelida to 

 other Eeptiles. He indicated certain peculiarities in the structure of 

 the vertebras which serve to characterize four great groups of Keptiles, 



