NEUROPTERA. — EPHEMERID&. 95 
or : \\ | } 
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N 

by the minute size of the antenne ; the unequal size of the wings; the 
membranous and almost obsolete mouth; and the elongated articu- 
lated setae at the extremity of the body. The body is long, slender, 
and soft ( fig. 61.1. Ephem. vulgata 3%, with the tails cut partly off) ; 
the head small, transverse-trigonate ; the eyes large, nearly oval, and 
lateral, in the males of some species very large, and meeting on the 
crown of the head *; the ocelli are three in number, and placed ina 
triangle between the eyes; the anterior ocellus being often small, and 
the two lateral ones placed on peduncles (fig. 61.16. head of Baetis) : 
the antennz are small, and 3-jointed ; the two basal joints thick; the 
third forming a long slender seta: the clypeus in some species 
(Baetis, jig. 61.16.) is large, fleshy, and shutting over the mouth with 


Curtis, in Taylor’s Philos. Mag. 1834. — Ditto, Brit. Ent. 
Dryander. Libr. Banks. sub Ephemera. 
Stephens, Savigny (Egypt), Fabricius, &c. 

* The males of Ephemera bioculata Z., in addition to the ordinary eyes, have the 
head furnished with two short, thick, erect pillars, on the top of which another pair of 
large eyes are fixed. Mr. Curtis doubts whether this insect has four wings; and 
the figure given by De Geer, vol. ii. tab. 18. f. 9., represents an insect with only two 
wings, although it has its head represented with pillared eyes. Geoffroy’s figure, 
vol. ii. tab. 13. f. 4., has four wings, two anal sete, and two very large eyes. The 
insects which appear to me to accord with the Linnzan description, have four wings ; 
but the posterior pair are very minute, with only two longitudinal nerves. The 
nerves of the anterior wings are exceedingly delicate ; and between each pair of the 
longitudinal nerves, at the tip of the wing, there are two very short nerves uncon- 
nected with any transverse nerve. These characters will bessufficient for the form- 
ation of this species into a separate genus, which may be named Brachyphlebia. 
It is perhaps equivalent to Stephens’s section z of Baetis, The Linnzan specimens 
are destroyed. 
