1374 Bulletin 4.7, United States National Museum. 



dd. Body rhomboidal, short and deep, with angular outlines, the depth 

 usually more than \ length ; spines long and slender ; second dorsal 

 spine | or more length of head ; second anal spine more than \ 

 length of head. PERUVIANUS, 1752. 



cc. Premaxillary groove broad, oval, and covered with scales (these some- 

 times deciduous in poorly preserved specimens). Anal rays III, 8; 

 second dorsal spine 1J in head; second anal spine Ig in head; teeth 

 rather long and slender. OLISTHOSTOMUS, 1753. 



GERBES : 



aa. Preorhital serrate ; a distinct dark streak along each row of scales on back and 

 sides; body rhomboidal, with angular outlines; spines very strong; anal rays 

 HI, 8 or 9- 

 e. Scales moderate or large, 34 to 39 in lateral line. 



/. Spines moderate, the second dorsal spine to | length of head. 



g. Pectorals short, barely reaching vent ; second dorsal spine 1| in head ; 



caudal shorter than head ; lateral stripes few ; depth about 2| in 



length ; 39 scales in lateral line. BREVIMANUS, 1754. 



gg. Pectorals long, about as long as head; caudal longer than head ; sides 



with numerous dark streaks along the rows of scales ; body deep, 



the back elevated, the depth 2 to 2J in length ; dorsal and ventrals 



more or less dusky. 



h. Pectorals as long as head, not reaching front of anal, 3 to 3 in 



body; scales 38; longest dorsal spine 1 in head, 

 t. Third dorsal spine rather longer than second; 10 rows of 

 scales between lateral line and vent; opercle with few if 

 any small scales at base. LINEATUS, 1755. 



ti. Third dorsal spine not longer than second; 11 rows of 

 scales between lateral line and vent; opercle with 

 numerous small scales at base. BRASILTANUS, 1756. 



hh. Pectorals very long, i longer than head, 2 to 2| in body ; sec- 

 ond dorsal spine longest, l\ in head ; scales 35. 



EMBRYX, 1757. 



//. Spines very high, the second dorsal spine longer than head; second anal 



spine about equal to length of head ; lateral stripes very distinct, about 



12 in number ; depth of body 2 in length ; pectorals very long, 2f in 



body; scales 37. PLUMIERI, 1758. 



ee. Scales small, 44 in lateral line. Second dorsal spine about as long as head ; 



depth of body 2 in length ; lateral stripes faint. MEXICANUS, 1759. 



Subgenus MOHARRA, Poey. 

 1750. GERRES RHOMBEUS, Cuvier & Valenciennes. 



Head 3J; depth 1^ ; eye 3| in head; snout 4; interorbital width 3J; 

 scales 5-38-10. D. IX, 10; A. II, 9. Body much compressed, rhomboidal 

 iii form, the back much elevated; profile evenly convex to supraorbital, 

 where there is a slight depression ; snout somewhat pointed ; mouth rather 

 large; end of maxillary reaching to vertical from center of pupil, its 

 Iength3 in head; exposed portion of maxillary oblong, its width about 

 2f in its length, which is 4^ in head; gill rakers stronger than in gula 

 or olisihostomuSj 18 below angle; premaxillary groove broad, oval, and 

 free from scales; pectoral fins reaching to front of anal, their length 3 in 

 length of body; ventral fins reaching beyond vent, their length 4J in 

 length of body; second dorsal spine stronger, but shorter than third 

 and fourth, its length about 4^ in length of body; margin of fin falcate; 

 suborbital entire; preopercle entire; caudal peduncle 2f in length of 



