54 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Oxychaetodon Bleeker, Arch. N4erland. Sci. Nat. Harlem, vol. 11, 1876, p.306. 

 Type Chaetodon lineolatus Cuvier, orthotypic. 



Gonochaetodon Bleeker, Arch. N^erland. Sci. Nat. Harlem, vol. 11, 1876, p. 

 306. Type Chaetodon triangulum (Van Hasselt) Cuvier, orthotypic. 



Anisochaetodon Kltjnzinger, Fische Roth. Meer., 1884, p. 54. Type Chae- 

 todon auriga Forskal, designated by Jordan, Genera of Fishes, pt. 4, 1920, 

 p. 429. 



Osteochromis Franz, Abh. Bayer. Akad. Wiss., suppl., vol. 1, 1910, p. 52. 

 Type Osteochromis larvatus Franz, monotypic. 



Tifia Jordan and Jordan, Mem. Carnegie Mus., vol. 10, 1922, p. 60. Type 

 Chaetodon corallicola Snyder, orthotypic. 



Body short, deep, very strongly compressed, especially above and 

 behind. Caudal peduncle short. Head small, compressed. Mouth 

 very small, terminal. Jaws with long, slender, flexible, bristlelike teeth. 

 Vomer sometimes with teeth. Preopercle entire or nearly so, with- 

 out spine. Gill openings rather narrow, membranes narrowly joined 

 to isthmus. Branchiostegals 6. Head almost entirely scaly. Trunk 

 with rather large ctenoid scales, somewhat irregularly arranged. Lat- 

 eral line curved, high, parallel with back. Dorsal fin single, continu- 

 ous, not notched, spinous part longer than soft. Dorsal spines about 

 13, not graduated, some of middle ones longer than last. Last soft 

 dorsal rays usually rapidly shortened, some occasionally filamentous- 

 Anal like soft dorsal, with 3 or 4 strong spines. Caudal fan shaped. 



A large genus of beautiful reef fishes of the tropical seas, mostly 

 living in the coral reefs of the Indo-Pacific. They are extremely 

 active and glide through the water with the greatest ease, often 

 quickly flashing their brilliant bodies. 



In the arrangement of the species we have largely followed Ahl. 



The following based on a young example is hardly identifiable: 



Chaetodon aphrodite Ogilby, Mem. Austral. Mus., vol. 2, 1889, p. 55, pi. 3, 

 fig. 2. Lord Howe Island. 



Black ocular bar. White blotch below spinous dorsal front. Whit- 

 ish vertical band from base of soft dorsal anteriorly to middle of tail. 

 Large oval black spot between 6 to 16 dorsal rays, below which brown 

 band suffused over entire anal base. Caudal gray, with narrow dark 

 brown basal band. Length 47 mm. (Ogilby.) 



We have examined the following examples of unidentifiable Thol- 

 ichthys stage: 



1 example. Mabullsland. September 29, 1909. Length 20 mm. (D. 5588). 

 1 example. Nogas Point. February 5, 1908. Length 20 mm. (D. 5129). 



