528 PROCEEDINGS OF THE NATIONAL MUSEUM. 



head and scaly at base; pectoral short, li in the head; ventrals equal 

 the head; caudal lunate and equal to the head. Color lost. Lateral 

 line complete. Length 17| inches (-150 mm.). 



This, the adult form, is well figured by Bleeker, differing from the 

 young chiefly in the lower fins. 



This species, very abundant in the East Indies and along the southern 

 coasts of China, is taken occasionally in the Kuro Shiwo off the coast 

 of Japan. Besides a number of specimens from Formosa, we have a 

 single one, obtained off Mi3'ako in Rikuchu, in Northern fTapan, pre- 

 sented to us by Mitonobu Irako, director of the museum at Morioka. 

 In the Imperial Museum at Tokyo are specimens from Tokyo, Kago- 

 shima, the Riukiu, and the Bonin Islands. In the Imperial University 

 is one from Okinawa and one from Kezen. 



According to Bleeker, this species is distinguished from Platax ves- 

 pei'tilio (Bloch) by its smaller scales. In PI. vespertiUo there are 20 

 to 25 scales between the lateral line and the first dorsal spine. The 

 dorsal rays in the latter are about V, 36. 



{orhlcularis, round. ) 



Family IV. CH.ETODONTID.E. 



BUTTERFLY-FISHES. 



Body strongh' compressed, elevated, suborbicular in outline, cov- 

 ered with moderate-sized or small scales, which are finely ciliated or 

 nearl}' smooth; lateral line present, concurrent with the back, not 

 extending on the caudal fin; mouth small, protractile, terminal; max- 

 illary verj" short, irregular in form, divided in two by a longitudinal 

 suture; upper part of skull solid, occipital crest strong; post-temporal 

 firndy joined to the skull, its form realh' trifurcate, though appearing 

 simple, the interspaces between the forks filled in by bone so that only 

 a foramen is left; last bone of suborbital ring firmly joined to the pre- 

 operculum; teeth brush-like or setiform, often extremely long, in 

 narrow bands in the jaws; no teeth on vomer or palatines; no canines, 

 molars, or incisors; eyes lateral, of moderate size; branchiostegals 6 

 or 7; pseudobranchite very large; air bladder present. Gill-mem- 

 branes more or less attached to the isthmus; gill rakers very small. 

 Dorsal fin single, continuous, its rays sometimes filamentous, its soft 

 part as well as the soft part of the anal densely covered with small 

 scales; anal similar to the soft dorsal with 3 or 4 spines; ventrals 

 thoracic, I, 5; caudal usually truncate. VertebrBS 10+14=24, the 

 anterior abljreviated; insertion of the ribs inferior; post-temporal 

 usually reduced, and not bifurcate. Carnivorous fishes of the tropical 

 seas, noted for their bright colors and great activity. The excessive 

 quickness of sense and motion enable these fishes to maintain them- 

 selves in the struggle for existence in the close competition of the 



