on the Ephemeride. 143 
Long. corp. ¢ 7-10, ¢ 5-10; set. gd 20-25, subim. 
9-15; set. 2 14-24, subim. 7-14; exp.al. ¢ 17-25, 9 
18°5-30 mm. 
Hab.—Rock Island, Illinois (Walsh) ; Indiana (Say). 
Heptagenia flavescens. 
(Genitalia maris, Pl. VI. fig. 16.) 
Palingenia (C) flavescens, Walsh, 1862. 
Subimago. <6. “ Ale vel subfuscescentes, colore ner- 
vorum indistinctiori quam in imagine; vel subflaves- 
centes, sub-opace, nervis flavescentibus, transversalibus 
in mediis apicesque versus exceptis. Segmentorum ab- 
dominis sex priora flava, strigis carentia. Setee invariz.” 
Imago, v. s. s. ¢. Thoracis tergum luteum, vel 
“rubiginosum vel piceum.” Alze vitrine, fulgore lacteo ; 
nervi picei, costis et subcostis majore parte flavescenti- 
bus exceptis ; punctum nodale indistinctum; arez mar- 
ginalis apex virescenti-griseo vel “ pallide rubiginoso” 
nebulosus. Pedum- antici sub-gambosi, vel “ pallide 
rubiginosi,’” femoribus bicinctis, apicibus juncturisque 
tibiarum et tarsorum fuscis; posteriores testacei, ‘ apici- 
bus femorum” juncturisque tarsorum obscuris. Abdo- 
men supra rufo-fuscum vel “rubigimosum,” juncturis 
obscuris ; sex priora segmentorum strigis pallidis duabus 
sub-distinctis, catera lutescentia: subtus testaceum, 
apicem versus lutescens. Sete albicantes, juncturis 
fuscis. ‘ Venter in v.s. pallide virescens, apice excepto.” 
2. © Pallidior, abdomine supra pallide fusco vel rubi- 
ginoso, carens vittis. Plurimi nervorum transversalium 
arez marginalis pellucidi.” (Walsh.) 
Long. corp. ¢ 9-13, @ 10-13; set. d 2 27-38, subim. 
3 17, 9 13; exp.al. ¢ 24-29, 9 27-34 mm. 
Hab.—Rock Island, Illinois (Walsh) .* 
* Heptagenia vitrea. 
Palingenia vitrea, Walk. 1853. 
Subimago, vy. s.s. @. ‘*Testacea; femora fusco sub-notata; ale al- 
bidx, sub-opace, nervis testaceis ’’ (Walker). 
Long. corp. 6, exp. al. 12 mm. 
Hab.—St. Martin’s Falls, Albany River, Hudson’s Bay. 
This species can be recognized in no other way, than by comparing 
specimens with the original type in the British Museum. 
