98 Mr. R. M‘Lachlan’s Monograph of the 
The female considerably larger than the male. 
Larva inhabiting clear running waters; the posterior pair of 
legs short. Case formed of small stones and sand, cylindrical, 
curved, smallest at the hinder extremity; when the larva is 
about to change it closes the larger opening of the case with a 
single flat stone. These larve are subject to the parasitic attacks 
of Agriotypus (see p. 82), and when thus attacked spin a silken 
band-like appendage. 
1. Odontocerus ulbicornis, Scopoli. (Pl. VI. fig. 1, neuration.) 
Phryganea albicornis, Scop. Ent. Carn. 1, 689 (1763); Oliv. 
Encye. Méthod. 6, p.155, 2; Mystacides albicornis, Pict. (*) 
Recherch. p. 162, 1, pl. 12, fig. 1; Odontocerus albicornis, 
Steph. (*) Ill. p. 192, 1, pl. 34, fig. 1; Brauer (*), Neurop. 
Aust. p. 18, 42; Hag. (*) Ent. Ann. 1860, p. 67, 55; Molanna 
albicornis, Kol. Gen. et Spec. Trichop. pt. 2, p. 244, 1, pl. 4, 
fig. 47; O. maculipennis, Curt. (*) Phil. Mag. p. 214, 2 
(1834); Steph. (*) Ill. p. 193, 23 Mystacides cylindrica, 
Pict.(*) Recherch. p. 164, 2, pl. 12, fig. 2 (1834). 
Antenne whitish-ochreous. Head and prothorax blackish, 
clothed with grey hairs. Palpi fuscous. Mesothorax black. Ante- 
rior wings ochreous-grey in the male, hoary in the female, with pale 
fuscous apical blotches, which are often indistinct ; transverse veins 
usually conspicuously fuscous. Posterior wings smoky-grey, with 
fuscous veins. The anterior pair of legs wholly fuscescent ; inter- 
mediate and posterior pairs with fuscous thighs and ochreous tibice 
and tarsi. Abdomen dull lurid-fuscous. In the male there is a 
band-like testaceous lobe, hairy at the tip, proceeding from the 
riddle of the truncated upper margin of the last abdominal seg- 
ment; app. sup. fuscous, large, flattened and obtuse, rather longer 
than the lobe; app. intermed. still longer, fine and needle-shaped, 
approximating at the tips; app. inf. strong, thick and obtuse, 
curved slightly upwards. In the female the superior valves are 
large and triangular, 
Expanse of fore-wings, g 13—14 lines, 9 16—18 lines. 
Larva with the head and thorax fawn-coloured, pointed with 
black. On the head there is a regular frontal spot, and two 
series of points extending from the eyes to the occiput. The three 
thoracic rings are narrowly bordered with black, and have several 
points of the same colour, Abdomen whitish. Feet fawn-coloured. 
(Pictet.) 
Not a very common species, but found about clear and swift 
streams in most parts of the country; specimens from Scotland are 
darker. 
