PERLID.«. — PERLA. 135 



Genus XXVI.— PERLA, Geoffroy. 



Antennae remote, inserted before the eyes at the base of the mandibles^ about 

 the length of the body, composed of numerous articulations, the basal one 

 stoutest and large, second smaller, remainder decreasing in size to the apex: 

 palpi unequal, subsetaceous, maxillary long, five-jointed; labial shorter, 

 triarticulate, in all the terminal joint most slender : labrum transverse, 

 linear : head large, much depressed, transverse-ovate : eyes lateral, promi- 

 nent: ocdli three: collar transverse-quadrate: meso- and meta- thorax 

 unequal : wings dissimilar in the sexes ; of the male not so long as the body, 

 of the females extending to the apex of the setae ; anterior pair elongate- 

 elliptic ; posterior shorter and broader, deeply incised on the outer edge : 

 abdomen short, sessile, furnished at its apex with two long jointed setse : legs 

 simple, longest in the males. 



The insects of this genus are usually of a large size, and the sexes 

 are very dissimilar, the males (which is rather extraordinary) having 

 the wings very much abbreviated ; their legs are also elongated, and 

 their general habit is very dissimilar to the females, which have large 

 expansive wings ; the legs are rather shorter than in the males ; both 

 sexes have the palpi of dissimilar length, the maxillary ones being 

 much longest, with the last joint slender, and the labrum is linear 

 and somewhat tubercular in the middle. 



Sp. 1. marginata. Fusca, capitis macnlis abdominis marginc Jlavescentibus, 

 antennis corpore longiuribus, thorace subtransverso. (Long. corp. $ 6 — 7 lin. ; 

 5 8—10 lin.; Exp. Alar. $ 9 lin. ; 9 1 unc. 11 lin. — 2 unc. 6 lin.) 



Pe. marginata. Fabricius.—Steph. Catal. 315. No. 3535. 



Fuscous : antennse as long as the body ; head moderate, black, varied with 

 yellow or ochreous, and with some glossy elevated spots ; thorax somewhat 

 transverse, with the disc rugged, a longitudinal dorsal channel, having an 

 elevated line on each side ; abdomen more or less ochreous, or yellowish, on 

 its sides and towards the apex; setse as long as the antennae, yellowish, 

 with fuscescent rings; legs with the tibiae and tarsi sometimes yellowish, or 

 dull ochreous ; wings fuscescent, wilh darker nervures, the fourth discoidal 

 areolet of the posterior pair simple. Pupa pale fuscous, spotted with 

 dusky. 



Variable both in size and in colour : in some examples, especially females, the 

 head is ochreous, or yellowish, with two black frontal spots; the thorax is 

 also occasionally varied with ochreous, and the legs are wholly of that 

 colour: — in this state I suspect the insect is the Per. flavipes, ia^re/'Z/e, 

 Hist. Nat. Crust. S^c. v. xiii. p. 49 ; and the larger specimens to be the Per* 

 grandis, Curtis, fol. 190. — Sfeph. Caial. 314. No. 3534. 



