94 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



PLEUROXICHTHYS Giraid. 



Form broad ; eyes and color on tlic rig^lit side. Month small : maxil- 

 lary narrow, short ; teeth in several series, slender, acnte, most devel- 

 oped on tlie blind side, j^o teeth on vomer or palate. Lips more or less 

 tliiclv. LoAver pharyngeals with a donble row of teeth. Gill-rakers 

 short, flexible. Anterior nostrils on both sides with a flap •, posterior 

 liatulons. Dorsal of less than eighty rays. Anal preceded by a spine ; 

 dorsal and anal rays simple. Branchiostegals seven ; no free preoper- 

 cnlar margin. 



Pleuroniciithys guttulatus Girard. 



IlijpsopscUa fjidtuUda Gill. 

 P(iroplir\js ayres'n Giiutlicr. 



D. GG-72. A. 47-54. P. 11-13. C. 3-12-3. Y. G. 



Form broadly oval ; the dorsal outline regularly curved from the snout 

 to the peduncle of the tail. Curve of snout meeting that of dorsal out- 

 line over the centre of the eye, forming a slight concavity. Abdominal 

 outline running downwards and backwards in a straight line to the origin 

 of the anal, thence to the caudal peduncle curved like the dorsal. Form, 

 including dorsal and anal fins, broadly rhombic. Height of body 

 nearly to quite half of the total length from the tip of the snout to that 

 of the caudal ; length of head nearly to rather more than ^ of the same ; 

 caudal peduncle ^-| of greatest depth. Snout short, about § of the 

 diameter of the orbit. Nostrils on a line with the upper margin of the 

 lower eye ; anterior nostril on both eyed and blind side with a fla]) behind ; 

 posterior patulous. Eyes about i of the length of the head, the lower 

 slightly in advance of the upper, which is slightly directed upwards. 

 Interocular space narrow, smooth, elevated, about -J- of the longitudinal 

 diameter of the eye. Mouth small, very oblique, lower jaw scarcely pro- 

 jecting, the tip of the mandible about level with the top of the pupil of 

 the lower eye ; maxillary reaching a little beyond the front margin of 

 the lower orl)it. Lips rather thick. A broad band of villiform teeth in 

 front in both jaws ; continued also along the blind side in tlie inter- 

 maxillary and the mandible, but along the colored side in the mandible 

 only. Pharyngeal teeth cardiform, in two or three irregular rows on 

 each upper pharyngeal bone, and in a double row on each of the lower. 

 Gill-rakers very short, blunt, flexible, distant. No free margin to pre- 

 operculum, the skin covering and uniting that bone to the other oper- 

 cular bones. Dorsal commencing a little in front of the centre of the 

 eye, highest about the 37th ray, which is about half the length of the 

 head. Dorsal and anal forming an obtuse rounded angle, giving the fish 

 a rhombic form. Anal usually with a spine, its longest rays opposite 

 and equal in length to those of dorsal ; its origin very slightly behind a 

 vertical from the posterior axil of the pectoral. Anal and dorsal coter- 



