PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 369 



Genus PSEUDOEHOMBUS Bleeker. 



(Cltcenopsetta and; Ancylopsetta Gill.) 



Iii Professor Gill's Catalogue of tlie Fishes of the East Coast of Xortli 

 America, from Greenland to Georgia (Proc. Acad. Nat. Sci. Phila. 1801), 

 many new genera are proposed without description or remark, most of 

 them being defined at a later period. Two of the genera of Flounders 

 there noted, CJuvnopsetta and Beinhardtius (proposed in 1861$ defined in 

 1861), are apparently identical with Pseudorhombtisjajid Platysomatickthys 

 of Bleeker, proposed and defined in 18G2. It is necessary, therefore, to 

 substitute the latter ill-chosen names for the preferable names of Dr. Gill, 

 if we hold with the present writers (and most others, — see Dall, Nomen- 

 clature of Zoology and Botany, 1877, pp. 17, 35) that a generic name 

 without a diagnosis, placed before the names of one or more species, has 

 no more claim on our recognition than an unpublished manuscript name. 

 The adoption of either is a matter of courtesy or convenience, not of duty. 



If the Pacific coast genus Paraliehthys is truly sinistral, as supposed 

 by Dr. Gill (Proc. Ac. Nat. Sci. Phila, 1801, 197), it is probably identi- 

 cal with Pseudorhombus, and as the prior name it should supersede the 

 latter. 



The genera of North American Flounders which seem to be worthy 

 of retention may be thus compared : 



* Pectoral fins well developed. (Pleuronectdxe.) 

 t Mouth large, the "broad, flat maxillary extending to below the eye ; teeth nearly 



equal on the two sides of the jaws, 

 t Ventral fins both lateral, neither of them on the ridge of the abdomen. (Hippo- 

 gloss ina\) 



a. Body dextral. 



b. Caudal fin emarginate ; teeth strong. 



0. Lateral line arched in front Hippoglossus. 



cc. Lateral line not arched Platysomatichtiiys. 



bb. Caudal fin entire, its middle rays produced; teeth moderate ; lateral line 



not arched. 



a". Dorsal beginning over eye; scales moderate, mostly ctenoid. 



HlPPOGLOSSOIDES. 



dd. Dorsal beginning in front of eye ; scales very small, cycloid. 



PSETTICIITHYS. 



aa. Body sinistral ; lateral line arched in front. 



e. Caudal fin entire. (Pseudorhombus or) Papaliciithys. 



ee. Caudal fin emarginate _ CJBOPSETTA. 



tt Ventral fin of the colored side on the ridge of the abdomen; body sinistral; 



teeth small. (Ilhombiiuv.) 

 f. Lateral line nearly straight ; no vomerine teeth: dorsal rays all 

 simple CITHARICHTHY8. 



ff. Lateral line arched in front ; vomer with teeth ; anterior rays of dor- 

 sal branched; scales cycloid... LOPHOPSETTA. 

 tt Mouth small, the short, narrow maxillary scarcely reaching beyond the front of 



tbe eye; teeth mostly on the blind side. 

 ( Pleuronectince.) 



y. Teeth slender, acute, in several scries; body dextral; lateral 

 line nearly straight, with a dorsal branch. 



Proc. Nat. Mus. 78 24 Mar. 1 1 , 1 8 79. 



