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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. Jsegeri, 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. 



By RICHARD OWEN, Esq., F.G.S., F.R.S., Instit. Reg. Sc. Paris. Corresp. 



[Read February 24, 1841.] 



Plates XLIII. to XLVII. 



At a preceding meeting I communicated the results of a microscopic examination 

 of the teeth of the so-called Mastodonsaurus Jesgeri 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 Salaman- 

 dro'ides and Mastodonsaurus were objectionable, I proposed that of Labyrinthodon, 

 as expressive of this peculiar dental structure, for the genus of reptiles thus cha- 

 racterizing 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 essen- 

 tially 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 



