GENERAL STRUCTURE AND ORDERS. 



1025 



of which the length is estimated at forty-five feet ; while Adenoderma 

 of the same deposits may indicate a distinct family. 



From the many resemblances presented by the Dolichosomatidce 

 to the existing Apoda, Dr Fritsch considers it probable that they 

 must be regarded as nearly related to the ancestral forms from which 

 that group has been derived. 



Suborder 3. Microsauria. — The Labyrinthodonts included in 

 this suborder resemble Lizards in outward appearance, and have 

 the centra of the vertebrae more or less elongated, and long, curved 

 ribs. 



Family Urocordylid^e. — This family — the Nectridea of Professor 

 Miall and the Ptyo?iiidce of Professor Cope — comprises stout, long- 



Fig. _954— Upper surface of the skull of Melanerpeton pusillum ; from the Permian of Bohe- 

 mia : six times natural size. B, Branchiae; O.s., supra-occipital; other letters as in fig. 950. 

 (After Fritsch.) 



tailed forms, in which the epiotic cornua of the skull are much pro- 

 duced : the cranial bones are pitted ; the neural spines and chevrons 

 of the caudal vertebrae are much dilated at their extremities and 

 pectinated ; and caudal ribs are wanting. The type genus Uro- 

 cordylus, as well as Ceraterpeton, occurs in the Carboniferous of 

 Britain and Ohio, and also in the Permian of Bohemia ; one species 

 of the former attaining a length of about twenty inches. Lepterpeton 

 is characteristic of the Carboniferous of Britain and Ohio ; other 



