58 Mr. R. M‘Lachlan’s Monograph of the 
low fenestrated spot, generally enclosing the whitish thyridium, is 
usually connected with a more or less distinct semilunate anasto- 
mosal space about the bases of the apical cells; veins brown, 
those of the anastomosis somewhat darker; upper margin of 
the discoidal cell rather deeply excised. Posterior wings whitish, 
subhyaline, yellowish towards the tips. Legs reddish-ochreous, 
with black spines. Abdomen brownish-ochreous above, paler 
beneath. In the male the upper margin of the last abdominal 
segment is cut off nearly straight, with a slight depression in the 
centre ; app. sup. concave internally, base broad, anterior margin 
deeply excised, the apex curved strongly inwards and very acute, 
the margins darker-coloured ; app. intermed. slightly diverging, 
blackish towards the tips; app. inf. only evident as a broad 
obliquely-truncated basal piece, fringed with long hairs; penis- 
sheaths with the tips slightly converging, piceous. 
Expanse of fore-wings 17—21 lines: 
The commonest species of the gente, appearing in May, and 
continuing for some months. 
I have not been able to make a comparison of the female ap- 
pendices of this and the next species from living examples, and 
have thought it advisable to say nothing about them in the de- 
scriptions. Both possess prominent lateral valves and a deeply 
trifid vulvar scale. 
2. Stenophylax vibex, Curtis. (PI. XI. fig. 1, app.) 
Limnephilus vibex, Curt. (*) Phil. Mag. p. 125, 30 (1834), and 
coll. part ; Stenophylax vibex, M‘Lach. Trans. Ent. Soe. ser. 
Seale COS. 
Antenne, head, palpi and thorax similar to the last species. 
Anterior wings precisely similar in form, and nearly so in 
coloration, perhaps slightly brighter ; the pale anterior margin 
is much broader and includes the area discoidalis. Posterior 
wings and legs as in the last species. Abdomen more decidedly 
ochreous above. In the male the upper margin of the last 
abdominal segment is cut off nearly straight; app. sup. obtusely 
spoon-shaped, the lower margin with a not very evident angle ; 
app. intermed. widely diverging ; app. inf. with a broad base pro- 
duced into a rather acute point (when viewed laterally), fringed 
with long hairs ; penis-sheaths as in the last species. 
Expanse of fore-wings 18—20 lines. 
Apparently less common than the preceding but widely dis- 
tributed. The place of capture of Curtis’ specimen is unknown; | 
