Notes on the Ephemeridce. 391 
of its genitalia quite corresponds with the figure in m)' 
Monograph. It is preserved in fluid. I suspect that my 
caution respecting dried specimens (Mon. p. 5Q) was 
therefore not altogether misplaced. When I Avas writing 
that caution, I had in my mind the resvdts of some early 
investigations of dried specimens, in the course of which 
I managed to fabricate two if not three species out of 
British and foreign examples of Ccenis macrura, and I do 
not know how many out of Hejitagenia elegans, all authen- 
ticated by camera lucida drawings of structures ! Is it not 
natural to be sceptical of drawings made from dried 
specimens after that ?] 
Page 57. C latipennis. — Palingenia umbrata, Hag. 
Syn., is a Campsurus in very bad condition : perhaps 
C. latipennis. The specimen is a little smaller than your 
dimensions. 
Page 58. — Pictet's Pal. puella is, after the figures, 
surely a Polymitarcys and not Campsurus. I believe it 
will go with B. alba. B. alba, Say, is a Polymitarcys. 
I caught it at Niagara Pahs at the end of August, swarm- 
ing just like P. virgo, to which species it is closely related, 
though distinct. It is undoubtedly Ephoron leukon, Wil- 
liamson, from New Jersey. I have a male from N. York, 
taken not so very far fr-om Belleville, N. Jersey. The 
colour of the abdomen alone would not agree. The type 
fr-om Red River is a female, and smaller than some males. 
The description of Say has apparently nothing in common 
with B. ferrugineus. Of coiu'se this is a matter of opinion. 
The reference to snow flakes makes me believe it to be a 
Polymitarcys. 
[I had not seen a Polymitarcys from America, and was 
inclined to suspect that the third seta in Pictet's figure 
was merely an artistic embellishment. With this bias, I 
was led to refer P. puella to Campsurus, that it might be 
near P. albicans. I was induced to attach some weight 
to Mr. Walsh's opinion about the relations of B. alba to 
B. ferrugineus, from the supposition that he would not 
have differed from Dr. Hagen without some good reason. 
I entirely concur with Dr. Hagen now.] 
Page 59. P. dorsalis, Burm. One of my (3 $) speci- 
mens is nearly as small as Pictet's type, the others larger. 
Burm. gives the length 10 lin. 
