PROCEEDINGS 
; OF 
THE GEOLOGICAL SOCIETY OF LONDON. 
Vou. III. Parr II. 1841. No. 74. 
Jan. 20.—William Lindley, Esq., Adelphi Terrace, Colonel Edgar 
Wyatt, and James Hastie, Esq., of Broad-street Buildmes, were 
elected Fellows of this Society. 
A paper was first read, ‘‘ On the Teeth of Species of the Genus 
Labyrinthodon (Mastodonsaurus Salamandroitdes, and Phytosaurus (?) 
of Jager) from the German Keuper and the Sandstone of Warwick 
and Leamington, by Richard Owen, Esq., F.G.S., F.R.S. 
The Warwick sandstone having been considered by some geolo- 
gists to be the equivalent of the Keuper*, and by others: of the 
Bunter Sandstein+, and as its true position remains to be deter- 
mined, Mr. Owen, in the preliminary remarks to his memoir, points 
out the assistance which the discovery of reptilian remains in the 
Warwick sandstone of the same generic characters as those of fossils 
obtained in the Keuper of Germany, may afford in determining the 
question. 
Before he proceeds to describe the fossils forming the immediate 
object of his paper, Mr. Owen shows that the genus Phytosaurus 
was established on the casts of the sockets of the teeth of Masto- 
donsaurus ; and that the latter generic appellation ought not to be 
retained, because it recalls unavoidably the idea of the mammalian 
genus Mastodon, or else a mammilloid form of the tooth, whereas all 
the teeth of the genus so designated are originally and, for the 
greater number, permanently of a cuspidate and not of a mammil- 
loid form ;'} and because the second element of the word, saurus, 
indicates a false affinity, the remains belonging, not to the Saurian, 
but to. the Batrachian order of Reptiles. For these reasons, and be- 
lieving that he has discovered the true and peculiarly distinctive 
dental characters of the fossil, he proposes to designate the genus by 
the term Labyrinthodon. 
The only portions of the Batrachian found in the Keuper of Ger- 
many, which have hitherto been described, consist of teeth, a frag- 
ment of the skull, and a few broken vertebre ; and in the Warwick 
sandstone of teeth only. In. this memoir, therefore, Mr. Owen 
confines his attention to a comparison of the dental structure of the 
Continental and English remains. The teeth of the Labyrinthodon 
Jaegeri (Mastodonsaurus Jaegeri, Meyer) of the Keuper are of a — 
—® See Proceedings, vol. ii. p, 453. + Ibid. vol. ii. p. 565. 
VOL, III, PART II, 2G ™ 
