1886.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 603 



ff. Body broadly ovate; scales small, cycloid, or wantiug; teeth subequal, 



in several rows; vertebrae 31 to 36. 



g. Scales obsolete or reduced in number, replaced in part by scattered bony 



tubercles on eyed side; dorsal with the anterior rays 



unbmnched and well connected by membrane; 



vertebra- about 31 Psetta. 



gg. Scales toell developed and regularly imbricate ; dorsal tvith the anterior 

 rays more or less branched, and imperfectly con- 

 nected by membrane; vertebras about 30. 

 gg 1 . Lateral line developed behind lower eye; dorsal tvith about seven 

 branched rays ; supramaxillary squarely truncate 

 behind and not produced at its lower angle; gill- 

 rakers about 4 -I- 12 BOTHUS. 



gg 2 . Lateral line not developed behind loiver eye; dorsal with eleven to 

 thirteen branched rays; supramaxillary obliquely 

 truncate behind, and produced at its lower angle; 



gjll-rakers about 8+22 Lophopsetta. 



ee. Vomer toothless; ventral fins free from anal; caudal fin subsessile. 

 ee l . Teeth distant and in one or two rows. 



ft. Lateral line with a distinct arch in front; teeth small, uniserial, 



or imperfectly biserial. 



i. Interorbital area a narrow ridge, sometimes with a median 



groove. 



j. Scales weakly ciliated or cycloid, deciduous ; vertebrw 10+28= 



38; supramaxillaries with a posterior process from 



the lower angle Arnoglossus. 



jj. Scales strongly ctenoid, adherent; supramaxillaries obliquely 



truncated behind Trichopsetta. 



ii. Interorbital space more or less broad, deeply concave; scales 

 small, ctenoid, adherent: body ovate (pectoral 

 of left side usually filamentous in the male) ; 



. vertebno (lunatus) 9+30=39 Platophrys. 



hh. Lateral line without arch in front; scales ciliated. 



k. Teeth in upper jaw biserial, in the lower uniserial, the 

 front teeth of the upper jaw enlarged ; vertebra; 



35 or 36 Syacium. 



kk. Teeth in both jaws uniserial ; interorbital space very nar- 

 row, the ridges coalescing between the eyes. 



I. Mouth not very small, the maxillary more than one- 



third length of head. 

 m. Gill-rakers very short and thick, tubercle-like; scales 



small, firm ctenoid Azevia. 



tarn. Gill-rakers slender, of moderate length ; scales thin, 



deciduous, ciliated ; vertebrae 34 to 40. 

 mm 1 . Head much compressed, tvith the interorbital region 



flat and level with the eye Citharichthys. 



mm 2 . Head moderately compressed, ivith the interorbital 



region sloping outwards and projecting over the 



lower eye Orthopsetta. 



II. Mouth very small, the maxillary less than one-third 



length of head Etropus. 



hhh. Lateral line without arch in front ; scales cycloid. 



kkk. Teeth in both jaws uniserial, of lower enlarged and largest on 



sides Cyceopsetta. 



ee 2 . Teeth crowded in villiform bands Thysonopsetta. 



