FISHES OF THE PHHjIPPINE AND ADJACENT SEAS 



281 



Body minutely asperous, velvety to touch; young with larger asper- 

 ities, velvety. 



D. VI, 27, I or 28, i, first spine 1^ to 2 in head, first ray 1^^ to 

 2}i; A. II, 27, I to 29, i, second spine 3 to 3%, first ray 2^4 to 3^; 

 caudal moderately emarginate, becomes slightly lunate with age, old 

 examples with hind edge nearly truncate, 3^ to 3% in combined 

 head and body, to tip of upper lobe Ito to 13/^ in head; least depth 

 of caudal peduncle 4 to 6^; pectoral IK to IH; ventral 13^ to 2}4; 

 caudal peduncle with 2 bucklers, each with compressed denticle and 

 though posterior denticle better developed anterior with longer base 

 or 1 to 1% in eye; young without bucklers. 



Fig. 21.— Rostral variation with age of Naso hexacanthus (Bleeker) 



Dull brown, slightly paler below sometimes, mostly uniform. Iris 

 brown. Dorsals deep brown to dusky or even blackish brown; smaller 

 examples with soft dorsal having 4 longitudinal blackish bands, fins 

 with age clouded to uniformly dark brown. Anals uniform dusky 

 and edges like dorsals, dark. Caudal and paired fins brown. 



Under the microscope the young show the teeth serrate. In the 

 adult they are inconspicuous, though present and much less devel- 

 oped. In this connection we have carefully compared the type of 

 Callicanthus metoposophron in the National Museum and feel certain 

 it is the younger stage of the present species. The teeth show dis- 

 tinct, though weak serrations, as in all our other specimens. 



