Thk Fresh Water Fishes ov the Island of Formosa. 173 



Body covered with small cycloid scales; head naked; lateral line 

 complete, extending along the middle of the sides, a little decurved. 



Color light l)luish green above, paler below; belly yellowish; dorsals, 

 pectorals, adipose dorsal, and caudal fin dusky; ventrals and anal 

 whitish. 



Total length 273 mm. 



Described from a specimen from Tamusui River near Shinten, 

 collected by T. Aoki in December, 1915 (Female). 



Habitat: Tamusui River; Choso River; Taiko, Giran. 



Remarks: The anal fin of the male is higher and shorter than that 

 of the female. The present species is distributed only in the rivers 

 of the northern part of the island, mainly in the Tamusui River. 



Measurements of Plecoglossus allivelis. 



Family SALANGID.E. 

 Genus Parasalanx Regan. 



1908 Parasalanx Regan, Ann. Mag. Nat. Hist. (8), II, p. 444. (Type Para- 

 salanx gracillitmis Regan.) 



Body slender, translucent, elongate, cylindrical, flattened anteriorly, 

 compressed posteriorly, naked. Head elongate, much depressed, 

 with long, flat, pointed snout; premaxillaries forming an anterior 

 triangular expansion; lower jaw not projecting, ending in a distinct, 

 more or or less movable presymphysial bone, with double series of 

 teeth; tongue toothless. Dorsal fin partly above the anal; adipose 

 fin present, small and low; caudal fin forked. 



Distribution: China; Formosa; Japan. 



Key to the Formosan Species. 



a. Depth of body ii times in length aciiliceps. 



aa. Depth of body more than 15 times in length ariakensis. 



