12 NEUROPTERA. 
more obliquely, and in some specimens is in direct continuity with that part of this 
nervure which precedes their junction; the posterior intercalar nervure of the 
pobrachial-anal interspace (7'=postical) is often detached from the pobrachial ; and the 
cross-veinlets are fewer or more restricted in their distribution. In the @ the posterior 
lateral angles of the dorsum of the eighth abdominal segment are nearly right-angled ; 
those of segment 9 acuminate, but not setaceously. In the ¢ (hitherto undescribed in 
detail in this genus) the forceps basis is entire; forceps-limbs apparently tri-articulate, 
with the basal joint nearly half the length of the whole ; penis exposed, turned upwards, 
narrow, bifid, with the points connivent. The head of the fly is conformable to that 
of Cenis. 
LEPTOHYPHES. 
Leptohyphes, Eaton, Ent. Monthly Mag. xviii. p. 208 (1882) ; Rev. Mon. Ephem. p. 140, t. 15. 
fig. 25 bis (1884). 
A small genus, previously known only by a single species from the Argentine 
Republic. 
1. Leptohyphes brevissimus, sp. n. (Tab. I. fig. 9, 2 .) 
Adult (dried).— 2. Body dark pitch-brown. Femora and extreme bases of tibie lighter pitch-brown; tarsi 
and remainder of tibiee impure whitish. Seta white. 
Length of body 2; wing 4°5-5°5 ; sete 2 millim. 
Hab. Guatemaua, Zapote (Champion; three ?@ ). 
But for M. Vayssiére’s representation of the subimago of Prosopistoma with hind 
wings [cf. Ann. des Sc. Nat. (6), Zool. xi. t. 1 (1881)], I would have suspected the fly 
of that nymph to bea Tricorythus, judging from the form of the @ thorax and abdomen 
in these genera, and their relative proportions. At all events, the nymph of Lepto- 
hyphes must be of very much the same make as Prosopistoma; and Canis ought not to 
intervene between them or be scheduled with Tricorythus and Leptohyphes so intimately 
as was done in my Revisional Monograph. Considerable latitude in subsidiary details 
of neuration must be allowed for when wings of individual specimens in any of these 
three genera are compared with published figures. In some wings of L. brevissimus, 
the second axillar nervure (92) is less strongly arched than in others (e. g. than in that 
one which is here represented), and sometimes the roundly curved first axillar dies away 
in the wing-membrane short of the margin; the intercalary nervures of the anal-axillar 
interspace also vary considerably in their mode of attachment, their common stem 
meeting the first axillar without any interposition of cross-veinlets, and being linked to 
the anal nervure by a single cross-veinlet placed at about the middle of their stem. 
The subulate membranous appendages that in some specimens project beyond the 
scutellum (as described in Rev. Mon. Ephem. p. 140) are probably distinctive of the 
