392 EHOPALOCEEA. 



POTAMANAX. 



Potamanax, Watson, P. Z. S. 1893, p. 55. 



This small genus contains eight or nine species, distinguished by their short primaries, 

 which, though not actually truncate, have the apex rounded and the costa short 

 relatively to the other margins. The palpi have a distinct porrect terminal joint; the 

 cell of the primaries is narrow and short ; the third median segment short, the second 

 long ; the lower and middle discocellulars are subequal, the lower radial slender ; the 

 third median segment of the secondaries is short, the second subcostal segment rather 

 longer, both discocellulars and radial very slender. The hind tibiee have two pairs of 

 spurs, but no tibial tuft. 



The range of Potamanax extends over the western portion of South America from 

 Peru northwards, spreading in Central America as far north as Nicaragua. Four 

 species occur within our limits. 



The male genitalia of a species allied to P. thestia, which we describe below as 

 Potamanax paralus *, have a tegumen ending in two widely divergent points, with a 

 short blunt point at the base on either side ; the scaphium is well developed, and ends 

 in two patches with granular surfaces ; the harpes are subtriangular and end in a 

 slightly upturned point about the middle of the dorsal edge, the margin is thickened 

 and granular, and between this and the apex are a few widely separated distinct 

 teeth, from the inner surface near the base is an erect slightly recurved lobe (See 

 Tab. LXXXVI. fig. 1.) 



l. Potamanax pammenes, s P . n. (Tab. lxxxvi. h gg . 2> 3.) 



Alls nigrieantibus, fascia communi lata a venae subcostalis anticarum medio ad angulum posticarum analem 

 alba, ad margmem anticarum internum flavo vix tincta : subtus dilutioribus, posticis usque ad basin 

 gnseo-albidis ; palpis infra albis. 



Bob. NicAEAgtJA, Chontales (Belt). 



This species is closely allied to P. unifasciata (Feld>) from Colombia, but differs in 

 having the apex of the primaries uniform, the diaphanous spots of P. unifasciata being 

 wholly absent. The inner margin of the white band of the primaries is not tinged 

 with rufous-orange ; but the whole band has a slight yellow shade where it runs out to 

 the inner margin. 



A species closely allied to P. pammenes occurs in Ecuador, differing in having the 

 white band of the secondaries more restricted and not continued to the inner margin 

 P. thoria is also closely allied, but has the common white band, especially on the 

 primaries, considerably narrower. 



* Potamanax paralus, sp. n. 



P. thestice affinis, sed fascia alarum communi multo angustiore, in posticis abbreviata. 

 Hob. Peru, Cosnipata Valley (If. WHtely). 

 This is the species referred by Mr. Druce to Pyrgus thestia (P. Z. 8. 1876, p. 249> 



