XXXII.— Description of parts of the Skeleton and Teeth of five species of the Genus Labyrinthodon (Lab. leptognathus, Lab. pachygnathus, and Lab. ventricosus, from the Coton-end and Cubbington Quarries of the Lower Warwick Sandstone ; Lab. Jægeri, from Guy’s Cliff, Warwick; and Lab. scutulatus, from Leamington ) ; with remarks on the probable identity of the Cheirotherium with this genus of extinct Batrachians.

Plates XLIII. to XLVII. At a preceding meeting I communicated the results of a microscopic examination of the teeth of the so-called Mastodonsaurus Jægeri of the German Keuper, and of the similarly-formed teeth of a reptile from the New Red Sandstone of Warwick, by which it was shown that they differed only in a slight or specific modification of a very peculiar generic structure, which distinguishes them from the teeth of all other reptiles, and apparently from those of all other animals; and as the terms Salamandroïdes and Mastodonsaurus were objectionable, I proposed that of Labyrinthodon , as expressive of this peculiar dental structure, for the genus of reptiles thus characterizing the British and Continental New Red Sandstones. There remained then, as a subject of interesting research, to determine from the fossils of the British strata referable to the genus Labyrinthodon , whether these would be confirmatory or subversive of its Batrachian nature, and whether, if essentially a Batrachian, its remains would manifest any or how great an affinity to the Saurian or any other order of cold-blooded animals. The means of contributing some facts towards the solution of these questions have been obligingly afforded me by Dr. Lloyd of Leamington since the transmission of my former paper to the Society. Having communicated to Dr. Lloyd the results of the microscopic examination of the tooth of the Labyrinthodon laniarius from the Coton-end quarry, he was so good as to bring up to London the whole of the collection of reptilian fossils from