122 Mr. R. M‘Lachlan’s Monograph of the 
white markings, viz., a broad band at the extreme base, reaching 
nearly across the wing ; a narrower band before the middle, also 
reaching nearly across the wing; two large triangular opposite 
spots, one on the costa and one on the dorsal margin, a little 
beyond the middle; and about eight small spots round the apical 
margin; neuration indistinct, the three transverse veins forming 
the anastomosis placed in an oblique interrupted line. Posterior 
wings grey, with grey fringes. Legs somewhat fuscescent, with 
a silvery lustre. Abdomen black with pale lateral lines. In the 
male there are two long needle-shaped and curved app. intermed., 
the left hand one being nearly twice the length of the right 
(1 have examined five males, and in every one I find that the 
app. intermed. are thus unequal; this in a single specimen I 
should have considered accidental) ; between these app. intermed. 
is an enormously long and slender needle-shaped upper penis- 
cover; app. inf. very long and slender, hairy, the points turned 
upwards. In the female there are two slender superior valves, 
and two broad and obtuse lateral valves. 
Expanse of fore-wings 63—73 lines. 
This elegant species was described by Fabricius from an English 
specimen in 1775, but was not re-discovered in this country until 
the year 1859, when a single example was taken at the canal at 
Taunton by Mr. Parfitt, the only native specimen that I have seen. 
I possess a fine series of the insect from Prussia. 
The name interruptus was erroneously applied by Donovan and 
Stephens to Leptocerus albifrons, Linn, 
Fam. HYDROPSYCHIDE. 
Antenne fine with long joints and longer than the wings, or 
stouter with short joints and shorter than the wings; ocelli 
generally absent; maxillary palpi alike in both sexes, long, 
searcely hairy, the terminal joint longer than the others, flexible 
and multiarticulate, or appearing to be made up of a number of 
very small joints, the sutures of which are readily seen in some 
genera, but are indistinct in others; labial palpi also with the 
terminal joint multiarticulate ; anterior wings generally dilated 
towards the apex, usually thinly clothed with hair, but sometimes 
with long and thiek hair; discoidal cell closed; posterior wings 
folded, usually shorter and broader than the anterior; legs spine- 
less, with the spurs variable in number, the posterior tibize always 
(in British genera) with two pairs of spurs. 
Larve elongate, tapering at the extremities, especially pos- 
