290 BULLETIN 180, UNITED STATES NATIONAL MUSEUM 



46. Caudal peduncle with spines or tubercles on center of at least some 

 of scales. 

 5a. Scales on side of trunk and on caudal peduncle with weak spines 

 or turbercles ; ground color pale, brownish above, abdomen paler ; 

 mouth with a narrow blue circular band around it from which 

 a blue streak extends to below pectorals and sometimes to anal 

 origin ; a narrow blackish band from spinous dorsal through 

 eye, thence curving to lower edge of pectoral fin base ; above 

 pectoral base a small black area with a narrow band extending 

 part way up to middle of base of spinous dorsal ; pubic spine 

 and ventral flap with dark brown margin ; pectoral, soft dorsal 

 and anal fins pale ; caudal pale dusky ; dorsal rays about III-27 



or 28, anal 25 or 26 ; scale rows on side of body about 54 



Balistes bursa Bloch 

 5&. Scales on anterior portion of trunk without spines or tubercles at 

 their centers, those on midside of caudal peduncle and adjoining 

 region just anteriorly with enlarged spines arranged in definite 

 rows. 

 6o. Caudal peduncle with four or five rows of moderately strong 

 spines, the three middle rows, with about seven to nine spines, 

 about equal in length and strength of spines ; area around these 

 spines with a triangular black patch, its base forming a black 

 ring around caudal peduncle ; anal rays about 21 ; dorsal III-23 

 to 25 ; pectoral 13 ; scale rows on side of body 37 to 40 ; ground 

 color of head and trunk pale ; a black band on interorbital 

 passes through eye, thence widens as it passes to base of pec- 

 toral and behind it to anus and anterior two-thirds of base of 

 anal fin ; upper edge of this patch and edges of triangular patch 

 on caudal peduncle pale (reddish in life) ; a pale line (reddish 

 in life) extends from near middle third of upper edge of black 

 patch to posterior base of soft dorsal ; pectoral, soft dorsal, 

 and anal fins pale ; caudal fin pale dusky ; membranes of 

 spinous dorsal blackish ; snout about three times in standard 



length Balistes rectangulus Bloch 



6&. Spines on the side area of caudal peduncle region not contained 

 in a definite black triangular patch. 

 7a. Caudal peduncle with three rows of strong, black spines, upper 

 two rows of about equal length, but lower row of about four 

 or five spines about half length of upper ; anal rays about 

 21 to 23; dorsal III-24 or 25; pectoral 13 or 14; scale rows 

 on side of body 39 to 44 ; ground color of body dusky above, 

 white below, with a blue-bordered or pale-bordered black 

 band from interorbital through eye to pectoral base, latter 

 with a black ring ; anus black ; a black patch with diffuse 

 edges extending from base of pectoral to origin of soft dorsal, 

 thence backward to caudal peduncle, but interrupted below 

 anterior half of soft dorsal by a pale triangular area ; from 

 black patch a black band extending downward and back 

 toward anus, then a black line followed by a black band 

 toward anal fin, these bands sometimes fading out before 

 reaching the ventral line ; blue band across snout ; pectoral, 

 soft dorsal, and anal pale ; spiny dorsal blackish ; caudal fin 

 dusky ; a ring of yellowish around snout and chin, connected 



