PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 369 



Genus PSEUDORHOMBUS Bleeker. 



{Ch(vno2)><ctta and AncuJojmita Gill.) 



In Professor Gill's Catalogue of the Fishes of the East Coast of North 

 America, from Greenland to Georgia (Proc. Acad. ISTat. Sci. Phila. 18GI), 

 many new genera are i)roposed without description or remark, most of 

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

 there noted, Cimnopsetta and Ecinhardtins (proposed in 1861; defined in 

 1864), are apparently identical with Pseudorhmnbus and Flafysomatichthys 

 of Bleeker, proposed and defined in 1862. 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 no more claim on our recognition than an unpublished manuscript name.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 Faralichthys is truly sinistral, as supposed 

 by Dr. Gill (Proc. Ac. Nat. Sci. Phda. 1864, 197), it is probably identi- 

 cal with Fseudorhombus, 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. (Pleuronectid^.) 

 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. {Htppo- 



glosdnce.) 

 a. Body dextral. 

 6. Caudal fin emarginat« ; teeth strong. 



c. Lateral line arched in front HiPPOGLOSStis. 



cc. Lateral line not arched Platysomatichthys. 



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



not arched. 

 d. Dorsal beginning over eye; scales moderate, mostly ctenoid. 



HiPPOGLOSSOIDES. 

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



PSETTICHTHYS. 



aa. Body sinistral ; lateral line arched in front. 



e. Caudal fin entire. (Pseiidcnhombm or) Paralichthy's. 



ee. Caudal fin emarginate Uropsetta. 



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



teeth small. (Ehovibinw.) 

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



simple ClxnARiciiTHYS. 



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

 sal branched; scales cycloid .. Loi'noi'SETXA. 

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



the eye ; teeth mostly on the blind side. 

 (Pleitronectma;.) 

 g. Teeth slender, ucute, in several series ; body dextral ; lateral 

 line nearly sfvuight, with a «lorsal branch. 



Proc. Nat. Mus. 78 24 Iflar. 1 1 , I 879. 



