186 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



GYMNOCROTAPHUS CURVIDENS Gunther 



Gymnocrotaphus curvidens Gunther, Cat. Fish. Brit. Mus., vol. 1, p. 432, 1859 

 (figure not published) (type locaHty: Cape of Good Hope). — Gilchrist, 

 Marine Biol. Rep. South Africa, No. 2, p. 92, 1914 (habits). — Gilchrist, 

 Marine Biol. Rep. South Africa, No. 3, p. 6, 1916 (eggs). — Thompson, 

 Marine Biol. Rep. South Africa, No. 4, p. 94, 1918. — Barnard, Ann. South 

 Afric. Mus., vol. 21, pt. 2, p. 727, 1927 (False Bay, East London). 



Depth 2 to 2K; head 3% to 3%. Eye 4 to 4% in head, 2 to 2% in 

 snout, 1}^ to 2 in interorbital, IK to 2 in preorbital depth; maxillary 

 reaches about % to eye; interorbital moderately high. Gill rakers 8 or 

 9 on lower branch of first arch, often 6 or 7 with age. 



Scales minutely ctenoid, 65 to 67 in lateral line; 6 or 7 above, 18 to 

 22 below. 



D.X, 12;A.III, 10. 



Yellowish brown, darker above and often with purplish tinge on 

 head. Iris blue. Fins grayish. Reaches 325 mm. (Barnard.) 



Said to be a vegetable or omnivorous feeder and an excellent food 

 fish. 



Family GIRELLIDAE 



Body oblong, deep. Head small, obtuse. Eye moderate or small. 

 Teeth in broad bands, all freely movable, each jaw with a series of 

 tricuspid incisors, usually followed close behind or within by broad 

 band of smaller ones. Suborbitals usually somewhat deep. Scales 

 on body moderate or small, 50 to 90 in lateral series. Opercles 

 scaly or naked. Soft dorsal, anal and caudal naked, or at least 

 terminally naked. Dorsal mostly continuous, spines graduated in 

 front, after which subequal. Caudal broad, little emarginate. 

 Paired fins small. 



Herbivorous fishes of tropical or subtropical shores, feeding on 

 seaweeds. 



analysis of genera 

 a^. Body ovate or elongate. 



hK Girellinae. Teeth tridentate. 



c*. Third dorsal spine not prolonged or greater in length than head. 

 d^. Opercle largely naked. 



e^. Scales 49 to 68; outer teeth in 1 to 4 rows Girella. 



e^. Scales 90; outer teeth uniserial Tephraeops. 



cP. Opercle scaly; scales in lateral line 80 Melambaphes. 



c*. Third dorsal spine longer than head Proteracanthus. 



¥. Crenideninae. Teeth crenulate; opercle scaly; preopercle flange naked; 



anal rays 9 or 10 Crenidens. 



a^. Tripterodoninae. Body orbicular; teeth tridentate; third to fifth dorsal 

 spines prolonged nearly twice length of head Tripterodon. 



