26 BULLETIN 214, UNITED STATES NATIONAL MUSEUM 



KEY TO THE SPECIES OF THE GENUS CHLORURUS 



la. Dorsal profile of snout straight, then profile bending abruptly over eyes and 

 nearly straight again to dorsal fin origin; uniform brownish in color, 

 except that young have pale spots; pectoral usually ii,14; 4 or 5 median 

 predorsal scales. Forehead becomes greatly enlarged on specimens 

 measuring l}i feet and longer; plate 7. (West Pacific, Indian Ocean.) 



gibbus (Riippell) 



16, Dorsal profile of head evenly arched from snout tip to dorsal origin; pectoral 



rays usually ii,12; median predorsal row of scales totaling 5 to 7. 



2a. Four to eight scales in third or ventral row of cheek; young with a large 



black spot at front of dorsal fin and a broad black bar across head, 



leaving snout and mouth pale; adults with lower part of body below 



lateral line with black spots numbering from one to several on each 



scale, the number of spots increasing with size; when alive background 



coloration pinkish to reddish brown; plate 8,a-c. (Central and 



West Pacific, Indian Ocean.) bicolor (Riippell) 



26. One to three scales in third, or ventral row on cheek. 



3a. No black spot on dorsal fin or black spots on scales; background colora- 

 tion brownish, or green when alive, with red or pale spots on head 

 above a line from mouth to pectoral base and pale spots on dor- 

 soanterior parts of body; a green band (brown in alcohol) from 

 below mouth, thence to below pectoral base to anus, bordered 

 above and below by orange (pale in alcohol) ; plate 6,c. (Central 



and West Pacific, Indian Ocean.) pulchellus (Riippell) 



36. A black spot may occur at front of dorsal fin or all median fins may be 

 black, except anterior part of dorsal yellowish; some black spots 

 may occur on scales of belly and breast; body and head yellowish; 

 plate 6,D. (Zanzibar.) , . . nigripinnis (Playfair and Giinther) 



Chlorurus gibbvis (Riippell) 



Plates 1,a; 7 



Scarus gibbus Riippell, Atlas zu der Reise im nordlichen Afrika . . . Fische des 



rothen Meers, p. 81, pi. 20, fig. 2, 1828 (type locality: Red Sea). 

 Scarus muricatus Cuvier and Valenciennes, Histoire naturelle des poissons, vol. 



14, p. 208, pi. 402, 1839 (type locality; Java.) 

 Pseudoscarus muricatus Bleeker, Atlas ichthyologique . . . , vol. 1, p. 26, pi. 7, 



fig. 3, 1862. 

 ? Pseudoscarus frontalis Macleay (not of Cuvier and Valenciennes) , Proc. Linn. 



Soc. New South Wales, p. 590, 1883 (type locality: New Guinea). 

 ? Callyodon macleayi Jordan and Seale, Bull. U. S. Bur. Fish., vol. 25 (1905), 



p. 331, 1906 (new name for Pseudoscarus frontalis Macleay, preoccupied). 

 Callyodon shimoniensis J. L. B. Smith, Ann. Mag. Nat. Hist., ser. 12, vol. 6, p. 



622, pis. 15, 16, 1953 (type locality: Kenya, Africa). 

 Chlorurus gibbus, J. L. B. Smith, Rhodes Univ. Ichthy. Bull. No. 1, p. 16, 1956 



(Mohilla, Red Sea). 

 Bolbometopon muricatus J. L. B. Smith, Rhodes Univ. Ichthy. BuU. No. 1, p. 8, 



plates 42h; 45a-d. 1956 (western Indian Ocean). 



This species with white teeth is characterized by 4 or 5 median 

 predorsal scales, 3 rows of scales on the cheek, with 1 or 2 scales in 

 the ventral (third) row; and usually ii,14 pectoral rays. The snout 



