138 Mr. R. M‘Lachlan’s Monograph of the 
termediate tibia with two pairs of long and unequal spurs; pos- 
terior tibize with two pairs of long and equal spurs. Abdomen 
short and stout, especially in the female. From beneath the 
upper margin of the last segment in the male proceeds a beak- 
shaped plate, placed over another smaller plate; app. sup. small 
and almost square ; app. inf. very long and bisarticulate, the second 
joint fureate, with a large upper fork curved at the apex, and a 
thinner nearly straight lower fork; penis cylindrical, directed 
downwards. The apex of the abdomen in the female is very ob- 
tuse, with two small rounded lateral valves, 
Larva inhabiting streams. Head elongate, the sides nearly 
parallel, somewhat truncated in front. Prcnotum short, small, 
nearly quadrate ; this and the head corneous. _Meso- and meta- 
nota broader, of the same consistency as the abdomen. Legs 
moderately long. Abdomen tapering behind, without external 
respiratory filaments; anal crotchets moderately long. 
Pupa elongate, the mandibles strongly dentate at the tips (PI. 
II, fig. 21); apex of the abdomen furnished with long appendices. 
Case an irregular heap of stony fragments. 
The pretty insects comprised in this genus attract the attention 
of the least observant. ‘They are found in great numbers about 
swiftly-running streams, preferring those of small size with rocky 
bottoms, such as are found in mountainous districts, 
1. Philopotamus scopulorum, Stephens. 
(Pl. VII. fig. 6, neuration, maxillary palpus, antenna; Pl. XIII. 
fig. 21, app.) 
Philopotamus scopulorum, (Leach, MS.), Steph. (*) Ill. p. 169, 
1 (1836); Hag. (*) Stett. Zeit. 1860, p. 277, 2; Ent. Ann. 
1861, p. 8, 98; Kol, Gen. et Spec. Trichop. pt. 2, p. 210, 4, 
pl. 2, fig. 15; P. variegatus, Steph. (*) Ul. p. 169, 2 (1836) ; 
P. montanus, Steph. (*) Ill. p. 170, 3 (1836); Hydropsyche 
montana, Pict.(*) Recherch. p. 210, 12, pl. 18, fig. 5; Philo- 
potamus tigrinus, Brauer (*) Neurop. Aust. p. 39 (1857). 
Antenne brown, annulated with yellow. Head black, with 
golden-yellow hairs. Palpi fuscous. Mesothorax black. An- 
terior wings brown, thickly spotted with yellow, many of. the 
spots being often confluent ; first apical cell (fork 1) reaching as 
far, or nearly as far, as the transverse vein closing the discoidal 
cell. Posterior wings blackish-grey, spotted with yellow round 
the apical margin; veins fuscous. Legs fulvous, the thighs 
fuscescent. Abdomen black. In the male the dorsal lobe from 
