210 MESSRS. HANCOCK AND ATTHEY 



great breadth of the entire skull, and their boundaries are marked 

 by strongly raised lines or ridges. The occipitals in combination 

 are quadrilateral, and are half an inch wide and six-tenths of an 

 inch long ; behind, the margin is slightly concave, and from the 

 sides, as if in continuation of the raised lateral lines, the two 

 inner cornua project ; they are a quarter of an inch long, are 

 conical and irregularly three- or four-sided, with the surface 

 roughened with ornamentation like that of the skull. 



In front the occipitals are divided from the parietals by a 

 double, raised, transverse line. The latter are as wide as the 

 occipitals, and have their lateral boundaries marked in the same 

 manner by raised lines, which are in continuation of those of 

 the occipitals, but are not so much elevated. These parietal 

 lines slightly incline towards each other as they advance for- 

 ward, which they do for about half an inch ; they then diverge 

 a little, and are lost in front in a circular groove which reaches 

 four-tenths of an inch further forward. The anterior boundary 

 of the parietals appears to be at the point where the lateral lines 

 are most approximate ; and in front of this the circular groove 

 may perhaps circumscribe the frontals and nasals. 



On the longitudinal middle line, a little in advance of the pos- 

 terior margin of the parietals, there is a circular foramen a tenth 

 of an inch wide, thus proving that we are correct in denominat- 

 ing this elongated area the parietals : consequently the area be- 

 hind must be that of the occipitals. But we must remark that 

 the forward position of the parietals, and the great extent of the 

 occipitals, are uncommon features in the Labyrinthodonts, and 

 seem to indicate an approximation to the Batrachian form of 

 structure — though, as we shall afterwards endeavour to show, 

 our new genus is more closely related to the recent genera Siren, 

 Proteus, and Axolotl. 



It is difficult to say of what bones the lateral expansions are 

 composed ; they remind us much of similar expansions seen in 

 other Labyrinthodonts, only they are proportionally much larger 

 than usual. Judging from this similarity, it may be assumed 

 that they are composed of the quadrates and squamosals, post- 

 orbitals and malars, so far as the posterior portions of them are 



