Note on Leucosparion petersi Hilg. 



BY 



T. Kitahara. 



With Plate V. 



This singular gobioid fish peculiar to Japan was first described and 

 named by H ILGENDORF of Berlin in the Berliner Monatsber., 1880. 

 Recently JORDAN and SNYDER of the United States have mentioned it 

 in the Proc. U. S. Nat. Mus. Vol. XXIII, 1901. So far as I can judge 

 from personal observations and trustworthy informations, this fish is 

 widely distributed over the Empire of Japan. It lives in the sea for 

 the greater part of the year and only in a particular season (that is 

 from the end of March to April) enters rather clear streams with gravelly 

 bottom where they spawn. Fishermen scarcely ever catch the fish in the 

 sea, because they are scattered over so wide a space of water. But they 

 offer in some districts an attractive sport to those who standing with his 

 dip-net on the bank of a stream would capture the tiny crystal fish just 

 as they enter the river mouth from the sea in schools. Before entering 

 the river the fish are usually slightly tinged with brown, which however 

 rapidly fades away while the head reddens in fresh water. In both the 

 male and the female there are stellate pigment spots on the operculum 

 and on both sides of the median line on the back. In the female, a special 

 series of somewhat conspicuous spots is present on each side of the 

 median line of the abdomen, along which an inconspicuous cutaneous 

 fold is to be seen (PI. V.,fig. 1). Very conspicuous in the living fish is the 

 globular air-bladder, seen through the flesh and bones in the hind paît 

 of the anterior half of the body, but missed by M ILGENDORF in pre- 

 served specimens. 



