

BY PROFESSOR STEPHENS, M.A., F.G.S. 1179 



two irregular protuberances about 10 mm. apart ; which I suppose 

 to indicate the epiotic cornua in a quasi cartilaginous condition. 

 Between them, I have once or twice thought, but hesitate to say, 

 that one of the two condyles was to be made out, in an equally 

 imperfect state. The appearance which suggested this may, 

 however, be really a trace of the atlas. 



Miall (I.e. p. 229) states — "That in Labyrinthodonts of the 

 carboniferous the occipital region appears scarcely ever to have 

 been ossified, and that owing to its cartilaginous character, it has 

 left little or no record." " In the Triassic Labyrinthodonts," he 

 continues," " the occipital region was fully ossified." But not, I 

 presume, in individuals so young as ours. 



Dimensions of Head. 



Length (about) , 27 mm. 



Breadth ,, 32 



Distance of orbit from base of skull 10 



Least width of interorbital space 8 



Length of orbit 8 



Width of orbit 6*5 



Distance of parietal foramen from base of skull 8 



From centre of occipuc to posterior end of orbit 14 



From tip of snout to anterior end of orbit (about) ... 9 



It is probable that these proportions of the skull would have 

 been different if the animal had attained a higher degree of 

 development. For as Miall says (I.e., p. 233.) "Like all the 

 bones of the face not only in Labyrinthodonts but in vertebrata 

 generally, the nasals become longer and longer relatively to the 

 brain case as age advances. This is notably the case with long- 

 snouted animals, such astheCrocodilia, and is mostapparent in those 

 species of Labyrinthodonts which have elongated skulls." And 

 again, "as the parietals lengthen with age the (parietal) foramen 

 is placed further and further back in the interparietal suture " 

 (ib. p. 234). In this case the foramen is about 8 mm. in advance 

 of the centre of the occiput, and about 2 mm. behind the line 

 joining the hindmost points of the orbits. 



