The Fresh Water Fishes of the Island of Formosa. 175 



snout and base of caudal, anterior ray longest; caudal fin deeply 

 forked, the tip of each lobe shar])K- i>()in(ed. 



Head and body naked. 



Color white, except eyes; two longitudinal series of small black spots 

 along the ventral median line. 



Total length 80 mm. 



Described from a specimen fron: Tamusui River near Taihoku, 

 collected by Oshima in February, 1917. 



Habitat: Tamusui River. 



Remarks: All the characters of the present species agree quite well 

 with those of the cotype in the Stanford University collections. 



In the year 1908, Regan noted in his paper (Ann. Mag. Nat. Hist. 



(8), II, p. 445) that Salanx ariakensis (Kishinouye) described by 



Jordan & Snyder might belong to the genus Ilemisalaivx . However, 



the lower jaw of the present species does not project and the premaxil- 



laries form an anterior triangular expansion. Such being the case, 



it seems reasonable to include Salanx ariakensis in the genus Parasal- 



anx. 



Measurements of Parasalanx ariakensis. 



Family SILURID.^. 

 Artificial Key to the Formosan Genera. 

 I. Dorsal fin spineless; anal very long. 



a. Dorsal fin many-rayed, very long, uniformly composed of feeble rays; 



four pairs of barbels Clarias. 



aa. Dorsal fin very short, rudimentary; two pairs of barbels. .Parasilurus. 

 J I. Dorsal fin with a pungent spine; anal moderate. 



a. Adipose dorsal fin not adnate, free behind; mental barbels as usual, 

 median pair not notably distant; dorsal spine smooth or denticulated; 



pectoral spine denticulated behind Pseudohagrus. 



aa. Adipose dorsal fin adnate to the back and connected with the caudal; 

 median mental barbels far apart; dorsal and pectoral spines smooth, 

 sharp, and imbedded in the skin Liobagrus. 



