20 MODERN CLASSIFICATION OF INSECTS. 
this I presume to be the male, and the preceding the male pupa of 
the same insect, which, from a consideration of its characters, I have 
separated as a distinct genus, named after Lachesis, one of the Fates. 
The Atropos pulsatorius (fig. 59.19.) is a minute, almost colourless 
insect, found in great numbers in ill-preserved collections of insects, 
plants, old books, &c., to which it is very injurious, by eating all the 
more minute portions; the different shape of the head, and proportion 
of the thoracic segments destitute of wings, united with its 3-jointed 
tarsi (fig. 59. 21.), and thickened hind legs, well distinguishes it from 
Psocus. Latreille, however, throws out a hint that it may be the 
larva of Psocus abdominalis ab. (pedicularius Latr. Hist. Nat. Ins. 
vol. xili. p. 71. and 73.), which scarcely appears to me to be possible ; 
although, from what I have noticed above, as to the variations oc- 
curring in Psocus, it is impossible to assert that such is not the case. 
Ihave noticed that they are killed in a very short time, when shut up 
in a box with camphor. This species is commonly called the death- 
watch, from its habit of making a slight tapping noise like the ticking 
of a watch, somewhat similar to that made by the species of Anobium. 
There are several papers in the early volumes of the Philosophical 
Transactions, above referred to, upon this subject. 
The genus Coniopteryx, placed by Curtis and Stephens in this 
family, evidently belongs to the Hemerobiide. 
The family Pertipm® * Leach, is of small extent, comprising but 
few species of moderate size (fig. 60.1. P. marginata), distinguished 
by the large size of the posterior pair of wings, which are folded, the 
3-jointed tarsi, the existence of labial palpi, and the ordinarily rudi- 
mental state of the mandibles, and membrano-coriaceous structure of 

* Brstiocr. Rerer. TO THE PERLIDA. 
Pictet. _Mém. sur les Larves des Nemoures, Ann. Se. Nat. August, 1832. — Ditto. 
on Perla, in ditto, January, 1833.— Ditto, in Mém. Soe. Physiq. et d’Hist, Nat. 
Geneve, vol. vii. (new Nemoure. ) 
Newman, in Entomological Magazine, vol.i. p. 415. (Isogenus.) Vol. iii. p. 500. 
(Chloroperla). Vol. v. p. 175. (Pteronareys and other North American species). 
Vol. vi. p. 401. Likewise a monograph of the caudated species about to be 
published. 
Suchow, in Zeitschr. Organische Phys. t. 11. No. 3. March, 1828. 
Lucas, in Ann. Se. Nat. December, 1832, t. xxvii. 
Westwood, in Griff. An. Kingd. (Eusthenia. ) 
Stephens, Olivier (Ene. Méth.) Curtis, &c. 
