REMAINS OF REPTILES AND FISHES. 79 



the centre in a radial direction, a double line of granular matter, 

 divided by a thin, clear, homogeneous substance. This com- 

 pound line takes an undulatory or zigzag course, and sends a 

 simple process from each angle into the lateral lobes or undula- 

 tions. The two granular lines are continuous with a similar line 

 that follows the sinuosities of the peripheral dentine ; and the 

 clear layer between these granular lines appears to be continu- 

 ous with the clear coating of the tooth, which would seem to be 

 composed of cement, the enamel probably not extending to the 

 base of the tooth. The Labyrinthodont structure of the tooth 

 would therefore appear to be formed by the vertical infolding or 

 plication of the peripheral wall of dentine and its external coat- 

 ing. It is evident, then, that the minute sti'ucture of the tooth 

 of Pteroiolax differs considerably from that of Anthracosaurus, in 

 which, according to Prof. Huxley, the radiating plicae are not 

 formed in this way. 



Ophideepeton NANtrM,"n. sp. 



A single individual of a curious serpent-like Labyrinthodont, 

 which apparently belongs to this genus, has been found at New- 

 sham ; it is not, however, in a good state of preservation, though 

 the characters are sufficiently distinct to permit of the determi- 

 nation of its specific and generic relations. From the head to 

 the caudal extremity, which appears imperfect, it is 5^ inches 

 long, allowing for the sinuosities : as it lies it is about an inch 

 shorter. The head is so much crushed that none of its charac- 

 ters can be determined. In its disturbed state, however, it is 

 T^otlis of an inch long, and nearly y-o-ths broad. Thirty-three 

 vertebrae can be counted in a pretty continuous series extending 

 from the head ; they may, however, be estimated at forty. They 

 do not appear to vary much in size : the largest are -rb-th of an 

 inch long, and they are decidedly hour-glass shaped. The pro- 

 cesses cannot be determined, though it is evident enough that 

 the spinous process is not much elevated, and that it is shorter 

 than the centrum. 



Numerous rather long, delicate, sUghtly curved ribs are scat- 

 tered along the sides, from the head almost to the caudal 



