Notes on the Ephemeridce. 397 
Page 90. At bottom insert — 
\_Leptophlebia mesoleuca. 
Potamantlius mesoleucus, Bran. 1857. 
Imago, V. s. s. Tergum thoracis aterrimum politiim. 
AlfB vitrin^e, venis fuscis ; anticis, nervis in arete costalis 
apice curvatis plerumqiie simplicibus. Pedes albi femo- 
ribns fuscescentibus ; antici saturation. Abdomen decolo- 
ratum, setis albis jvincturis obscuratioribus. Forceps albus. 
Penis appendicidatus, segmentis ejus appendiculis parum 
brevioribus ; his paulo eis L. modestce latioribus. 
Long. Corp. 6 — 7 mm. ; set. circa 8 mm. 
Hah. — " Im Prater an Siimpfen. Juni." (Brau.) 
Mr. Albarda drew my attention to my having overlooked 
Brauer's Supplement, at p. 74 bis of his Neuroptera 
Austriaca, and sent me types from Brauer of the Baetis 
sulphurea and Pot. mesoleucus there described. The former 
is not Pictet's species (which is Heptagenia elegans, Curt.) 
but another, which is allied to Heptagenia Jlavipeiinis , 
wanting the bands on the femora. It will have to be re- 
named. From the type (^ im.) of the second of Brauer's 
species, I was able to determine the relations of L. meso- 
leuca. It has the forceps and adjacent ventral plate very 
like those of L modesta ; but the apical joint is as long as 
the second, and each of them is as long as the first.] 
Page 93. Ccenis macrura {halterata. Fab., Hag.). I 
have before me a lot in a phial dry, perhaps more than a 
thousand. They are from Rismansfelds, a little bath-place 
near the Frisch HafF, where in the gardens the tables are 
covered with them in the morning, to the depth of some 
inches. Pictet, p. 42, relates nearly the same thing of 
his C. lactea. I have specimens from Eastern Prussia, 
(Konigsberg.) 
Page 94. Ccenis lactea, Pict. (? chironomiformis , Curt.). 
I possess a lot sent by Bremi " 17th June, 1854, very 
common on the lake at Zurich." This is apparently 
Pictet's species, and I had it with me in London, but none 
of the specimens in Stephens' collection agreed with them. 
But this is not my halterata, nor the lactea of Burmeister. 
I believe that C. chironomiformis, Steph., was j of my 
halterata \i. e. of macrura.^ 
Page 95. Ccenis dimidiata {lactea, Burm., Hag. ; E. 
