NEUROPTERA. — PSOCIDE. 7 
The reader who would learn more ample particulars relative to 
the natural history of these insects, their various duties, the internal 
economy of the nest, and their wonderful instincts, must consult 
Smeathman’s Memoir above referred to, Kirby and Spence’s Jnéro- 
duction, vols. i. and ii., and Latreille’s Hist. Nat. vol. iii., as well as 
my article Termitide in the Brit. Cyclop. of Nat. Hist. The spe- 
cies of this family are evidently more numerous than has been sup- 
posed, but they require a more rigorous investigation than has hitherto 
been given to them. Some exotic species (jig. 60. 16.), having 3-jointed 
tarsi, wings not longer than the body, and the anterior legs dilated 
(60.18.17. maxilla), compose the genus Embia Laér. They seem more 
nearly related to the Perlida. They form the subject of my mono- 
graph, published in the Linnean Trans. vol. xvii. 
The family Psocip * Leach. comprises a rather numerous series 
of minute insects, at once distinguished by the almost obsolete la- 
bial palpi; the 2 or 3-jointed tarsi; the smaller size of the posterior 
wings, which are not folded, and by the slenderness of the antenne, 
which are long and setaceous, composed of about thirteen joints ; the 
first of which is the largest, the third the longest, and the remainder 
gradually diminishing in length ; the upper lip is large; the man- 
dibles (fig. 59. 2.3.) horny, trigonate, with a tooth near the tip in- 
side, and another (much stronger in one jaw than the other), near 
the base inside ; the maxille (jig. 59. 4.) are elongated, fleshy at 
the tip, and armed with a long, slender, curved, horny process, aris- 
ing from the base, and longer than the maxille ; the maxillary palpi 
are 4-jointed ; the labial apparatus (jig. 59.5.) is large; the mentum 
is a large leathery plate, reaching to the base of the head beneath; 
the labium subquadrate, with a deep, longitudinal, central impression ; 
the sides are rather rounded, and the middle, in front, produced into 

* Brsriocr. REFER. TO THE Psocip&, 
Latreille, in Bull. Soc. Philomat. an. 3. Nos. 41. and 42, — Ditto, in Coquebert. 
Illustr. Ieconogr. Ins. tab. 2. 
Phil. Trans. 1693, Allen; 1701, Derham ; 1724, Stackhouse.*( Atropos pulsatorium. ) 
Nitzsch., in Germar, Mag. Ent. vol. ivy. (Anatomy Atropos pulsator. ) 
Carpenter, in Mag. Nat. Hist. No. 10. 
Stephens, Curtis, Fabricius. 
VOL. II. Cc 
