158 Miscellaneous, 



the tooth of Labyrinthodoii, this dentine, or ivory, is composed of 

 calcigerous tubes To^^jth of a line in diameter, radiating and con- 

 verging with primary curvatures and secondary undulations in a 

 manner unexampled in the history of dentition. This gigantic Ba- 

 trachian prototype of the Bull Frog, Mr. Owen has discovered to 

 be the author of the footsteps ascribed to the so-called Chirothe- 

 rium. Teeth of two smaller species of Labyrinthodon have been 

 found by Dr. Lloyd in the sandstone of Warwick, and although no 

 English teeth of the Stutgard species have yet been submitted to 

 the microscope, Mr. Owen strongly suspects that the cast of a large 

 jaw containing several teeth, from Guy's Cliff, near Warwick, the 

 original of which has been mislaid in the Oxford Museum, is iden- 

 tical with the Labyrinthodon Salamandroides of Stutgard; thus 

 almost demonstrating the evidence required by Mr. Murchison and 

 Mr. Strickland * to show the identity of the Warwick and Guy's 

 Cliff sandstones with the keuper of Germany. Mr. Owen con- 

 cludes, that if on the one hand geology has derived essential aid 

 from minute anatomy, in no instance has the comparative anatomist 

 been more indebted to geology than for the fossils which have re- 

 vealed the most singular and complicated modification of dental 

 structure hitherto known, and of which no conception could have 

 been gained from an investigation of the teeth of living animals. 



Professor Owen has communicated to us a Report on two new 

 fossil reptiles, recently acquired by Sir P. Egerton from the chalk 

 of Kent : one of them a tortoise, allied to the Chelonians which 

 now live in fresh water, or in estuaries ; the other a small Saurian, 

 which has teeth generically distinct from any known Lacertians, 

 and resembling the points of stout packing-needles ; to this new 

 lizard in the chalk he has given the name Raphiosaurus. 



Mr. Mackeson has discovered in the bottom of the lower green- 

 sand formation near Hythe a very large tibia and several other 

 bones which he refers to the Iguanodon, spread in the quarry over 

 a length of fifteen feet ; in the same quarry were a large Ammo- 

 nite, a Gervillia, and other marine shells characteristic of the lower 

 greensand. We have in these bones another case similar to that of 

 the nearly entire skeleton of Iguanodon found in the greensand near 

 Maidstone, and transferred with Mr. Mantell's collection to the 

 British Museum ; showing the duration of the Iguanodon to have 

 extended beyond the period of the Wealden freshwater formation 

 into that of the greensand. In both these cases the carcases must 

 have been drifted into salt water from some not far distant land, 

 the site of which we cannot conjecture to have been nearer than 

 Devonshire, Normandy, or the Ardennes. 



ICHTHYOLITES. 



Respecting the bone-bed in the Severn near Aust Passage, and at 

 Axmouth Cliff near Lyme Regis, which has hitherto been referred 

 to the bottom of the lias formation. Sir P. Egerton and M. Agassiz 

 have found ichthyological reasons for considering it to be connected 

 with the Triassic or new red sandstone group ; because they find in it 



* Geol. Trans., N.S., vol. v. p. 345. 



