KEMAINS OF REPTILES AND FISHES. 69 



related to Loxomma, resembles not a little, in the general form 

 of the skull, as far as it can be determined, Dasyceps Bucklandi.'^- 

 The concavity of the occipital margin and the two lateral cornua 

 are very similar in both species ; but in the latter, these pro- 

 cesses or horns are more robust, and do not look so spine-like 

 as in Pterojylax cornuta. The proportions and forms of the com- 

 ponent bones, too, are very different ; and the parietal foramen 

 in Dasyceps is much nearer the occipital margin, as are also the 

 orbits, which are likewise very much smaller. The resemblance, 

 also, of these cranial bones to those of Keraterpeton cannot be 

 overlooked, so far as they can be compared. The general form 

 of the crown of the head, with the narrow projecting frontals and 

 concave occipital margin, together with the " j)Ostero-internla 

 cornua," are all remarkably alike in the two forms; but, from 

 the deficiency of surface sculpture in that animal, and its com- 

 parative smallness, it would seem that they cannot be considered 

 congeneric. 



Four left premaxillaries have been obtained ; and all of them 

 have a portion of the nasal bone attached, as well as several teeth 

 more or less perfect. The premaxillary is about 2^ inches long, 

 and upwards of half-an-inch wide ; it is arched most strongly 

 towards the anterior symphysis, which is oblique and coexten- 

 sive with the width of the bone ; behind it is prolonged, the 

 articular portion being wedge-shaped ; the surface is strongly 

 sculptured into elevated anastomosing ridges and depressions ; 

 and they all exhibit two strong, wide, round grooves on the ex- 

 ternal surface, one of which passes from the front, the other 

 from behind, converging and meeting at nearly a right angle, 

 close to the alveolar margin. These grooves are similar to what 

 have been denominated mucus-grooves in the Labyrinthodonts, 

 and are exceedingly like those figured and described by Prof. 

 Owen on the muzzle of Labyrinthodon leptognatlius.\ And in 

 this instance they seem to indicate the boundary of the nasal 

 bone, which is apparently of a lozenge form, probably somewhat 

 prolonged backwards. Half the circumference of an external 



*" Memoirs " Geological Survey, 1S59, p. 52. 

 t "Trnnsnctions" Geological Society, Ser. 2, Vol. VI., p. 417, Plato XLIII.. (ig. 1. 



