LABYRINTHODONTIA 1 93 



breadth is thirteen lines. The ridges are moderately thick and 

 compact, with a central medullary cavity. In its structure, 

 as well as in its general form, the present bone agrees with the 

 batrachian, and differs from the crocodilian type. 



In the right ilium, about six inches in length, and in the 

 acetabulum, there is a combination of crocodilian and batra- 

 chian characters. The acetabular cavity is bounded on its 

 upper part by a produced and sharp ridge, as in the frog, and 

 not emarginate at its anterior part, as in the crocodile. 



As the fragment of the ilium was discovered in the same 

 block as the two fragments of the cranium and the portion of 

 the lower jaws, it is probable that they may have belonged to 

 the same animal ; and if so, as the portions of the head corres- 

 pond in size with those of the head of a crocodile six or seven 

 feet in length, but the acetabular cavity with that of a crocodile 

 twenty-five feet in length, then the hinder extremities of the 

 Lahyrinthodon must have been of disproportionate magnitude 

 compared with those of existing Saurians, but of approximate 

 magnitude with some of the living anourous Batrachians. 

 That such a reptile, of a size equal to that of the species 

 whose remains have just been described, existed at the period 

 of the formation of the new red sandstone, is abundantly mani- 

 fested by the remains of those singular impressions to which 

 the term Cheiroth&rivm has been applied. Other impressions, 

 as those of the Cheirother •mm Hercules, correspond in size with 

 the remains of the Lain rial hoi] on salamandro'idcs, which have 

 been discovered at Guy's Cliff. The head of a femur from the 

 same quarry in which the ilium was found is shown to corres- 

 pond in size with the articulate cavity of the acetabulum. 

 The two toe-bones, or terminal phalanges, resemble those of 

 Batrachians in presenting no trace of a nail, and from their size 

 they may be referred to the hind feet of the L. pachygnatJms. 



An entire skull of the largest species discovered in the 

 nevr red sandstones of Wurtemberg ; a lower jaw of the same 



o 



