19. ZANCLUS. 493 



prseoperculiim without spine. Scales minute, rough. Air-bladder 

 present ; branchiostegals four. Pyloric appendages in increased 

 number. 



Indian Ocean and Archipelago ; Polynesia. 



1. Zanclus comutus. 



Benard, i. 13. 76, ii. 9. 44, ii. 16. 75 ; Ruysch, tab. 1. f. 3 ; Valunt. iii. 



f. 168.456; Seba,m.. 25. 6. 

 Cbsetodon, Artedi, Si/non. p. 79. 



Tetragonopterus, sp., Klein, Miss. iv. tab. 12. f. 2 & 3. 

 Chffitodon cornutus, L. Si/st. p. 461 ; Bl. taf. 200. f. 2 ; JBI. Schn. p. 221 ; 



Lacep. iv. p. 473. pi. 2. f. 1. 

 Zanclus comutus, Cuv. Sf Val. vii. p. 102. pi. 177 ; Sleeker, Vcrhand, 



Butav. Genootsch. xxiii. Chcetod. p. 22. 

 Gonopterus moerens, Gronov. Syst. ed. Gray, p. 77. 

 Skeleton : Rosenthal, Ichthyot. Tafeln, tab. 13. f. 3 ; Agass. MecJierch. 



Poiss. Foss. iv. tab. G. 



B. 4. D. fj. A. |. Cffic. pylor. 14. Vert. 9/13. 



A pointed horn above each orbit (in adult specimens). The third 

 dorsal spine exceedingly elongate, filiform. Two broad black cross- 

 bands from the dorsal fin to the beUj ; caudal black, vnth. the poste- 

 rior margui white, crescent-shaped. 



Indian Ocean and Ai'chipelago ; Polynesia. 



a. Yery fine specimen. Amboyna. From Mr. Frank's Collection. 

 h. Half-grown. Amboyna. From Mr. Frank's Collection. 



c. Half-grown. Ceram. From Madame Ida Pfeiffer's Collection. 



d. Half-gro^Ti : stuflPed. Sandwich Islands. 



e. Adult : not good state. 

 /. Advdt : not good state, 

 r/. Adult. 



h. Adult. From the Haslar Collection. 



i, k. Half-grown : bad state. From the Haslar Collection. 



1. Half-grown. From the Haslar Collection. 



m. Adult. Old Collection. 



n. Adult : discoloured. Old Collection. 



0. Half-grown : skin. From Gronow's Collection. 



p. Adult : skeleton. From the Collection of the Zoological Society. 



The skeleton has been described and figured by several authors ; 

 the anterior and posterior portions of its vertebral cohunn are so 

 shortened in their longitudinal diameter, that, at both extremities, 

 one vertebra has not been developed. 



2. Zanclus canescens. 



Seha, iii. 25. 7. 



Chajtodon canescens, Artedi, Spec. p. 93 ; L. Syst. Nat. i. p. 460 ; Bl, 



Schti. p. 219. 

 Zanclus ceutroguatbiis, Cuv. ^- Val. Aii. p. 528. 



No horn on the forehead ; praeorbital with a strong spine above 



