on the Hphemeride. 57 
conformibus. <4 seta media caret; pedum posteriores 
brevissimi, antici longi femoribus imprimis brevissimis ; 
ultimi segmentorum latera breviter producuntur. ? sete 
tres equales; pedes breves debillimi (etiam antici); 
ovivalvula caret. 
The genus Campsurus occupies in America the posi- 
tion of Polymitarcys in the Old World. Many species of 
this genus are so alike in colour that it is difficult to 
discover. the females. Their habitat is probably limited 
to large rivers of a tolerably high temperature. 
Campsurus latipennis. 
(Genitalia maris, Pl. III. fig. 10, 10a.) 
Palingenia latipennis, Walk. 1853 (non var.). 
Imago, v. s. s. 6 @. Thorax fusco-luteus; pro- 
thorax tumescens, a fronte angustus, sulco longitudmali 
medio, et foveis lateralibus, alter pone oculos subtrian- 
gulari, alterdque apud coxam utrinque. Alarum anticarum 
area marginalis usque ad tertiam partem ab apice fusces- 
cens, nervis transversalibus tenuibus subrectis simplicibus 
paucis claudentibus. Pedes antici fusci. Abdomen supra 
lined elevati longitudinali media, et posterioribus seg- 
mentorum fuscis; infra testaceum. Set cretacex. 
hongeeorpy. 99-7; al. ¢ 8, 9 9;-set.. ¢-22imm. 
Hab.—Para. 
Campsurus albifilum. 
(Genitalia maris, Pl. III. fig. 11.) 
Palingenia albifilum, Walk. 1853. 
Imago, v.s.s. ¢. Thorax fusco-testaceus; prothorax 
veluti in sp. preecedente. Ale pellucidz, anteriores ner- 
vorum cretacei; transversales apicales arez marginalis 
anticee pauci subrecti. Pedes antici fusci, coxis testaceis. 
Abdomen ochraceum, setis albis ; segmentorum apicalium 
quatuor, ceeterum juncture, et lez longitudinalis ele- 
vate dorsalis margines, cinereo tinct. Forceps et penis 
pallide lutescentes. Sete albe. 
Long. corp. ¢ 12, al. 13, set. 47 mm. 
Hab.—Para. 
