EDWIN CHAPIN STARKS 29 



back as a groove, and the top of the head is covered with a moderately thick 

 skin. The supraoccipital process barely reaches to the dorsal plate. The 

 adipose dorsal is situated over the anal and is about equal to it in length. 

 The anal is emarginate and the caudal is forked. 



96. Plat3rpogon caenilorostiis Starks, new species. 



Plate 5. 



The head is conical, as deep as wide opposite the posterior edge of 

 the operculum, and equal to two-thirds of its length. It is contained 4 

 times in the length of the body to the caudal base. The depth of the 

 body slightly exceeds its width, and is contained from 5^ to 5^ in the 

 length. The depth of the narrowest part of the caudal peduncle is con- 

 tained from 3^3 to 3^ times in the head. The skin forms a moderately 

 thick covering to the bones of the top of the head, forming a smooth 

 surface with fine striations barely indicated. The fontanel does not extend 

 behind the eye, and a very short groove, not longer than the pupil, extends 

 back and terminates abruptly. This is only made evident by removing the 

 skin. The occipital process tapers back to a rather narrow point at the 

 dorsal plate, being scarcely, or barely, in contact with it and not at all con- 

 nected. The eye is large and round. Its diameter is contained 2^ times 

 in the interorbital space, 6 times in the head, and 2^ times in the snout. 

 The premaxillary band of teeth is widest at the middle, where it is equal 

 to two-thirds of the diameter of the eye. The teeth grow long posteriorly 

 and lie flat, pointing straight backward. The vomerine and palatine patches 

 of teeth form a continuous band, a little narrower than the premaxillary 

 band, and slightly narrower in the middle than at either side. All of the 

 teeth are freely movable. The snout is convex above, and moderately 

 broadly rounded in front. Its length is contained 3 times in the head. 

 The rictus reaches to under the anterior margin of the eye. The barbels 

 have a membraneous posterior margin, especially tlte mentals and post- 

 mentals, where the membrane is as wide, or a little wider, than the fleshy 

 part of the barbel. The maxillary barbels reach to the base of the ventrals, 

 the postmental barbels a little past the middle of the pectorals, and the 

 mental barbels to the base of the pectorals. 



The dorsal spine is filamentous, a third longer than the head, and 

 reaches to the adipose dorsal. The dorsal has 6 rays, and its base is con- 

 tained 23/2 times in the space between it and the adipose dorsal. The base 

 of the adipose dorsal is almost as long as that of the anal, and is situated 

 directly opposite to it. Its vertical height is half of the length of its base. 



