290 



rnocEEDixas of the national museum. 



distance between tip of snout and posterior border of eye, the depressed 

 Hu usiijillv lullin.u- short of base of anal, in some cases reaching it. 

 Anal base very h)no-, the posterior rays highest, about equal in height 

 to those of dorsal, oxtendino- to base of caudal when depressed. Pec- 

 torals inserted partly below median line of body, their length contained 

 about -tiT times in body. Ventrals pointed, short; just reaching vont 

 when depressed. Caudal truncate, -i^ in the loigth. 



Color in alcohol, light brownish, the silvery coating of peritoneum 

 showing through walls of abdomen; a narrow, median, dusky stripe 

 extending along back from occiput to dorsal; sides of body sparsely 

 stippled with black, the edges of scales dusky; a median, dusky line 

 extending along sides of body from tip of pectoral to base of caudal; 

 mem))ranes of fins dusk}', the color deepening toward the edges; ven- 

 trals l)lack; a narrow light area on base of caudal. 



^ 4 J 



Oryzias latipes. 



The above description is of a male example. The female has a more 

 slender body, especially in the region posterior to anal opening; the 

 anal is lower and the ventrals are usually longer, often reaching 

 beyond base of anal. The ventrals are immaculate or only slightly 

 dusky. No modification of the anal rays appears to distinguish either 

 sex. 



Many specimens were secured from a stagnant pool at Wakanoura, 

 and an equal number from a ditch in a rice Held at Kawatana, on the 

 bay of Omura, to the northward of Nagasaki, in company with the 

 minnow B/iodeus oryzx. Specimens were also received from Prof. 

 Keinosuke Otaki from pools or brooks near Tokyo. 



It is very common in all mosquito-breeding waters in southern Japan. 



{I at us, broad; jh's, foot.) 



