The Fresh Water Fishes of the Island of Formosa. 265 



variety of Augiiilla japonica, tliough minor differences exist between 

 these two forms, as shown in the following table of relative proportions: 



Formosan 

 A. "Japonica. Eel. 



Total length loo.oo loo.oo 



Distance from gill-opening to the origin of dorsal. . 18.18 18.41 



Length of head 12.35 12.70 



Distance from gill-opening to vent 27.20 28.45 



Distance from tip of snout to origin of dorsal 30.54 3i-ii 



Distance between origins of dorsal and anal fins. . . 9.76 10.31 



Length of pectoral 4-0i 4-77 



Length of upper jaw 3-24 3-20 



Length of snout 2.16 2.14 



Diameter of eye 1.02 i.ii 



Interorbital space 1.92 2.06 



Height of body in front of anus 521 5.40 



Ratio of pre-anal and post-anal parts i :i-53 i ' i-47 



Number of vertebras iiS-65 ii5-57 



Moreover, he has regarded Anguilla remifera from Hokoto which 

 was described by Jordan & Evermann {Proc. U. S. Nat. Miis., XXV, 

 1903, p. 325) as being also a variety of A. japonica, because the dis- 

 tinctive characters of that species, that is, longer and rather pointed 

 pectoral fins (2.17 in head) and the distance from front of dorsal to 

 front of anal slightly more than length of head, are the points which 

 are to be seen in extreme variations among examples of A. japonica 

 {Joiirn. Coll. Agriciil., IV , 1914, p- 426). 



Four specimens of an eel in the Stanford collections (No. 21 181; 

 Takao, Formosa) which had been described by Jordan and Richardson 

 under the name Anguilla sinensis were examined and compared with 

 my specimens of the common Formosan eel. It appears that in the 

 former the distance from gill-opening to origin of dorsal, distance 

 from gill-opening to vent, distance from tip of snout to origin of dorsal, 

 diameter of eye, and height of body in front of anus (average length) 

 are somewhat greater, while the length of head, distance between 

 origins of dorsal and anal, length of pectoral, length of upper jaw, 

 length of snout, interorbital space are smaller. As shown in the fol- 

 lowing tables (III, V), however, these characters are variable and 

 have no specific value. 



