ICHTHYOLOGY OF VENEZUELA — SCHULTZ 65 



Genus HYPOPOMUS Gill 



Hypopomus Gill, Proc. Acad. Nat. Sci. Philadelphia, 1864, p. 152. (Genotype, 

 Rhamphichthys mulleri Kaup.) 



After examining the material in the national collections, along with 

 four specimens collected by Dr. William Beebe at Caripito, Venezuela, 

 and comparing these with figures and descriptions of the already 

 described species, I have considerable doubt as to the identifications 

 made by Ellis in his review of the family Gymnotidae and by Eigen- 

 mann in his work on British Guiana fishes. (The two accounts are 

 nearly identical.) The specimens from Caripito have a very bluntly 

 rounded snout and shorter head, and the pore above the posterior 

 nostril differs in position when compared with forms from other 

 localities. Unfortunately, Kaup did not show the position of that 

 pore in reference to the posterior nostril, but his measurements of 

 and his figure of artedi indicate that this species has a pointed snout 

 with the rear margin of the eye behind the middle of the length from 

 snout to occiput, while in other forms it is equidistant between, as 

 shown in figures and in the specimens before me. Steindachner's 

 figure of brevirostris fortunately shows the position of the pores in 

 reference to the posterior nostril, and these are the same as in the 

 specimens that I am referring to occidentalis Regan from Panama and 

 the Maracaibo Basin, but the species must be dift'erent since brevirostris 

 has 259 or 260 anal rays instead of fewer than 240 in the other species. 

 Because of the above differences it appears probable that the speci- 

 mens from Caripito represent a distinct species, whereas those from 

 the Maracaibo Basin are so close to those from Panama that I 

 identify them as the same form. Measurements made on available 

 specimens are recorded in table 9. 



KEY TO THE SPECIES OP HYPOPOMUS 



la. Anal rays about 259 or 260; pore above posterior nostril (see fig. 9) lying 

 behind a vertical line through rear edge of posterior nostril and this pore 

 more remote from nostril than nostril is from edge of eye; tail behind anal 

 fin rounded, tapering to a point, and length of tail contained about 4 times 

 in total length; distance from posterior nostril to eye contained about 10 

 to 15 times in snout to occiput (Rfo Guapor^). 



Hsrpopomus brevirostris (Steindachner) 

 lb. Anal rays fewer than 240, usually from 204 to 238. 



2a. Rear margin of eye at least one-half to an eye diameter behind middle of 

 length of distance from snout to occiput; snout contained 2.5 to 3 times 

 in the head and about 1% in postorbital length of head; distance from 

 posterior nostril to eye contained about 15 times in length from snout to 

 occiput; pore above posterior nostril lying behind a vertical line through 

 rear edge of nostril (Rfo Mona, French Guiana). 



H37poporQus artedi (Kaup)" 



1' Rhamphichthys mulleri Kaup is referred to this species as a synonym. I have examined a specimen of 

 artedi. I. U. 12620, kindly lent by Dr. J. L. Kask, California Academy of Sciences, and refer it to this species. 



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