436 Mr. A. Alcock on undescrihed Shore-Fishes 



of the maxilla is nearly ^ that of the head. Teeth numerous, 

 close-set, even, acute, uniserial, in both jaws. 



Gill-membranes united ; ,2:ill-rakers few, short. Scales of 

 moderate size, adherent ; thick and strongly ctenoid on the 

 coloured, cycloid on the blind side. Lateral line with a 

 supra-pectoral curve ; its scales small and faintly bilobed. 

 The longest dorsal rays, which exceed the corresponding 

 anal rays, are ^ the body-height. Paired fins mucli more 

 developed on the coloured side, where the pectoral has its 

 upper rays prolonged equal to ^ the length of the body 

 measui-ed without the caudal. 



Colours in life : — Left side brown, with irregular black 

 blotches, the three largest of which are on the lateral line, 

 while the others form a series round the body ; several trans- 

 verse series of deep blue spots in the interorbital space ante- 

 riorly ; right side with a transverse black band behind the 

 mouth and with a number of indefinite dark blotches arranged 

 in a large triangular patch in the middle of the body. 



Total length 3'75 inches. 



Off the soutli-east coast of Ceylon, 32 fathoms, as above. 



This species is closely allied to the next preceding, and the 

 single specimen appears to hi a male. 



At several stations off the Ganjam coast there have been 

 taken some curious dwarf Pleuronectids which, in consequence 

 of their diminutive size and the transparency of their tissues, 

 one is at first inclined to regard as either larval or stunted 

 forms. But in the relative proportions of the body, in the 

 completed asymmetry (shown in the unilateral disposition of 

 the eyes, the unilateral restriction of pigment, and the slight 

 unilateral atrophy of the paired fins), in the perfect ossifica- 

 tion of the skeleton, and in the cliaracter of the vertical fins, 

 one sees indications of development sufficiently advanced to 

 permit of tolerably accurate generic and specific discrimina- 

 tion. The outline of the body is like that of Rhombus, but 

 more circular; the nature of the mouth and dentition and the 

 disposition of the eyes are similar to Rhomhoidichthys. 



PSETTYLLIS, gen. nov. 



Allied to Rhomhoidichthys ? 



Body subcircular. Jaws and dentition symmetrical ; mouth 

 very small, the length of the maxilla being less than one 

 fourth that of the head ; teeth minute, in the jaws only. 

 Eyes on the left side, separated by a broad concave space. 



