on the Ephemeride. 69 
Vertex capitis maculd lutea: prothorax lineis longitudi- 
nalibus duabus atris; mesothorax supra macula magna 
lutescente, ex qui in fronte et a posteriore strigze cur- 
vate due producuntur; metathorax luteus, maculis 
L-formatis nigris duabus. 
Imago, v.v.s. d. Caput atrum, oculis supra fuligi- 
nosis, infra vel paulo saturatioribus vel nigris. Thoracis 
tergum aterrimum nitens. Ale virescenti-grisez vel 
pallidissime flavo-virentes, maculis piceis et nervis atris : 
posteriores marginibus terminalibus late, et nervis trans- 
versalibus anguste, griseo tinctis. Pedes olivacei; antici 
femoribus atro-piceis, et tarsis fuscis; posteriores tibiis 
tarsisque fulvis, apicibus articulorum ultimorum et ungui- 
bus fuscis. Abdomen umbrino-olivaceum, juncturis et 
apicibus segmentorum plus aut minus ochraceis: trian- 
gulos acutos duos, lineasque interpositas breves duas, 
segmentorum posteriorum supra quidque habet, infraque 
lneas longitudinales atras quatuor, viz., duas longas 
sub-parallelas, et duas breves divergentes: in anteriori- 
bus segmentorum trianguli in strigis curvatis se conver- 
tunt, et notule interposite obsolescuntur. Setz fusce, 
juncturis fuliginosis, atque pubescentes, preecipue apices 
versus. Forceps fuscus. 
? plane omnino mari similis, alis pallidioribus ex- 
ceptis. 
Var. $ et 9,v.v.s. Pro maculis trigonalibus, lines 
curvate segmentis singulis sunt. 
Long. corp. 14-22; al. ¢ 16-17, 2 18-24; set. ¢ im. 
33 & 34-32 & 36, subim. 16 & 17-19°5 & 21; set. 2 im. 
22 & 24-26, subim. 17 & 16-18 & 19 mm. 
|  Hab.—Moscow (Oul.); Scandinavia (Zet.); England, 
, Germany, France, and Switzerland. May and June. 
This species is plentiful in warm rivers and tranquil 
streams in England, and in some of the Swiss lakes (e. g., 
near Brunnig). 
Ephemera guttulata. 
(Genitalia maris, Pl. LV. fig. 6, 6a. Maculee abdominales, 
fig. 6b.) 
Ephemera guttulata, Pict. 1843-5. Ephemera deeora, 
E. simulans & Palingenia natata, Walk. 1853. Ephemera 
natata, Hag. 1861. 
