70 Rey. A. HE. Eaton’s Monograph 
Subimago, v. s. 8s. ¢ @?. Ale vix nigricantes, 
maculis et marginibus nervorum transversalium piceis. 
Pedes purpureo-brunnei. Sete fuliginose, juncturis 
obscuris. 
Imago, v.s.s. &. Ale vitrine, in nervis transversa- 
libus piceo crebre maculate. Pedes et sete lutei, junc- 
turis fuscescentibus. Macule magne dorsi abdominis 
transverse, subquadrate, angulis posticis retro pro- 
ductis, et lateribus emarginatis: venter bilineatus. 
? simillima, alis sparse maculatis. 
Long. corp. ¢ 11, ? 18-15; al. g 18-15, ¢ 15-19; 
set. ¢ im. 25, subim. 14; set. @ subim. 15 mm. 
Hab.—From Northern Illinois and from Connecticut 
northwards ; in rivers. 
This species resembles H. vulgata in having the back 
of the abdomen spotted instead of being merely streaked, 
and also in the general formation of the male genital 
organs. M. Pictet’s specimen seems, from the figure, to 
have been a male imago. 
Ephemera flaveola. 
Li. flaveola, Walsh, 1862. 
Subimago, v.s.s. ‘Ale fumate. Sete obscure et 
pallide virescentes.” 
Imago, v. s. ¢. “Vertex capitis rubiginosus ; ter- 
gum thoracis pallidius. Ale vitrine; anticee apud costas 
flavescenti-tinctz, et tribus prioribus nervorum longitu- 
dinalium flavescentibus. Pedes flavescentes; antici 
apicibus femorum et tibiarum, proximis articulorum tar- 
Salium et apicibus juncturisque ceterum, rubiginosis. 
Abdomen flavescens, strigd pallidé utrinque segmentorum 
3-7. Setz albicantes, juncturis fuscis.” 
9 v.s. Abdomen vitelli-coloratum. Nervi trans- 
versales alarum fusci, eis ad apices et apud margines 
terminales exceptis.” 
Long. corp. ¢ 7°5-9°5, ¢ 9-10°5; set. g im. 20& 
14, subim. 12 & 10; set. 9 im. 12 & 10; exp.al. ¢ 17- 
19, @ 19-20. (Walsh.) 
Hab.—Rock Island, Illinois (Walsh) ; and New York. 
