NO. 1319. 



SO^fE JAPANESE FISHES— JORDAN AND STARKS. 



541 



lo. CYPSILURUS AGOO (Schlegel). 

 TOBI-NO-UWO (FISH OF FLIGHT:) TOBISUWO (FLYING-FISH): AGU. 



Exoccetus agoo Schlegel, Fauna Japonica, Poiss., 1846, p. 247; Nagasaki, from 

 a drawing. — Ishikawa, Prel. Cat., 1897, p. 18; Tokyo. 



Cypselnriis agoo Jordan and Snyder, Check List Fishes of Japan, 1901, p. 60; 

 Yokohama. 



Exoccetus doderleini Steindachner, Fische Japans, IV, 1887, p. 38; Tokyo. 



Cgpselurus doderleini Jordan and Snyder, Check List, 1901, p. 60; Yokohama. 



Head, 4^ in length; depth, of to 6i. Dorsal, 13 or 1-i; anal, 8 or 9; 

 scales, 52; eye, 3i to 3i in head. 



The depth of head and bodj^ is very variable; in some specimens the 

 opercle is l)roadly rounded; in others it slants upward and backward 

 more obliquely and has a slight flap. Between these extremes there 

 are all intermediate conditions. 



The pectoral reaches in the shortest examples nearly or quite to 

 the base of the last dorsal ray; in the longest to the tips of the last 

 declined dorsal ray. The simple upper ray is contained about If 

 times in the length of the entire fin. The second ray is branched, its 



Fig. 3.— CYPSILURUS agoo. 



lower branch the longel-, and reaches to within from 1 to 2 times the 

 diameter of the eye to the tip of the third or longest ray. The suc- 

 ceeding raj^s rapidl}^ and uniformh^ diminish in length to the ninth 

 ray, and thence more rapidly to the last. 



The ventrals reach from slighth^ beyond the middle to the end of 

 the anal base. The base of the dorsal is contained from 1^ to li in 

 head; that of the anal, 2i to 2f . 



Color in spirits slaty brown on back, shading to silvery on lower 

 parts of head and body; when scales are lost, as in most of our speci- 

 mens, the color is bluer and the edges of the scale pouches are con- 

 spicuously dark. The maxillary is dusky; a dark band is on eye 

 around and above upper part of iris. The ventrals are white on lower 

 surface, on upper either white or slightly dusky along the outer rays; 

 nearly always the base of the first ray is dusky. In the closed pecto- 

 ral the upper rays to their tips appear lighter than the median rays, 

 which grow gradually darker to black toward their tips. The mem- 

 brane is bluish black, fading out below and colorless between lower 

 I'ays. Color in life metallic bluish above. 

 Proc. N. M. vol. xxvi— 02 37 



