Jordan and Ever maun. Fishes of North America. 1687 



regularly arched, but approaching the dorsal outline posteriorly, ceas- 

 ing before reaching end of dorsal. Scales below lateral line regularly 

 arranged, those above irregular. Color in alcohol, uniform gray (prob- 

 ably orange in life) ; scales edged with silvery ; a very faint, narrow, black 

 or dark-blue edge to dorsal anterior to filament ; terminal half of pectoral, 

 of caudal, and tips of dorsal and anal behind and including the falcate 

 lobes yellow; no blue on concavity of dorsal and anal; lips pale; edge of 

 opercle dark blue; a faint indication of a dark blotch in front of dorsal; 

 no blue-black blotch on base of pectoral. This species differs from Angel- 

 ichthys ciliaris in the form of the body, in color, and especially in the very 

 long spines on the upper limb of preopercle. A single specimen, 9 inches 

 long, from the Galapagos Islands, collected by United States Fish Com- 

 mission steamer Albatross, (lodonos, a sheaf of arrows, from the brist- 

 ling preopercle.) 



Ifolacanthus iodocus, JORDAN & HUTTER, in Gilbert, Proc. U. S. Nat. Mus. 1896, 445, Gala- 

 pagos Archipelago (Type, No. 47747, TJ. S. Nat. Mus. Coll. Albatross) ; JORDAN & 

 EVEKMANN, Check-List Fishes, 421, 1896 ; name only. 



Family CLXVI. ZANCLID^E. 

 (TiiE MOORISH IDOLS.) 



Body oblong, much compressed and elevated, covered with minute rough 

 scales. Mouth small, with long, slender, brush like teeth ; no teeth on the 

 palate ; bones of top of head thick and solid, developing with age a con- 

 spicuous median horn on the forehead, wanting in the young. Preoper- 

 cle unarmed. Dorsal single, with 7 spines, the third and succeeding 

 spines prolonged into long filaments ; interspinal bone projecting before 

 dorsal. Anal similar to soft dorsal, long, with its anterior rays produced; 

 a small antrorse spine before anal. Caudal peduncle unarmed, the fin 

 lunate; pectorals short; ventrals pointed. Intestine long. Coracoid 

 bones largely developed. Vertebra reduced in number, 9 -f 13 = 22. Air 

 bladder large. Branch iostegals 4; pyloric cajca 14. One species, widely 

 distributed about rocky islands of the Pacific. (Genus Zanclm, Gunther, 

 Cat., n, 492-494, 1860.) 



663. ZANCLUS, Cuvier & Valenciennes. 



Zanclus (COMMERSON) CUVIER & VALENCIENNES, Hist. Nat. Poiss., vn, 102, 1831 (cornutus). 



Gonopterus, GRONOW, Cat. Fish., Ed. Gray., 77, 1854 (mcerens). 



Gnatkocentrum, GUICHENOT, Ann. Maine et Loire, ix, 4, 1866, (centrognathum) ; young. 



Characters of the genus included above, (^dynkov, a sickle.) 



2103. ZANILUS CORNUTUS (Linnaeus). 

 (MOORISH IDOL; BESAN; PIQUIER; PORTE ENSEIGNE.) 



Head 2? ; depth about as great as length; eye 2^ in snout. D. VII, 38; 

 A. Ill, 33; snout H in head, greatly produced, the upper profile very con- 

 cave; horn on forehead well developed, wanting in young; teeth slender, 

 brush-like, very much projecting. Anterior rays of dorsal and anal pro- 



