PACHYGASTRIA TRIFOLII. 25 



although not sharply defined. The skin is covered with a coat of 

 minute bristles, and the hairs are serrated rather than thorny (not 

 unlike those of Trichiura crataegi only more marked.) No free 

 secondary hairs are yet present on dorsal area, and they are either absent 

 or very sparse on the lateral areas. There is as yet no trace of the 

 lateral and dorsal thoracic markings that are present in potatoria, and 

 in a somewhat different form in quercils and quercifolia *(Bacot). The 

 adult larva is thickly covered with golden-brown hairs on back, which 

 are erected medially on each segment ; laterally the brown colour is 

 less distinct, and there are a few black hairs on the thoracic segments, 

 and four little tufts on abdominal segments ; area below spiracular line 

 and the venter, dull black, covered with grey hairs. Head variable 

 in colour, thickly covered with black and white hairs, with tiny black 

 spots at bases, dull slaty-blue, shaded with bright orange-red, with 

 a dark band down either side of the clypeus, which, with a border 

 outside it, is whitish-brown ; ocelli, small, shining, black, placed on a 

 red-brown patch • prothorax, with a dorsal chitinous-looking black 

 patch mottled with orange-red, bearing a transverse series of tubercles 

 carrying bright reddish golden hairs, two small bunches of black hairs, 

 laterally; meso- and metathorax, with subdorsal groups of black hairs, 

 each divided into three (or four) subsegments; laterally a large round supra- 

 spiracular black tuft, and smaller black tuft in spiracular line. Abdo- 

 minal segments, each divided into four (or five) ill-marked subsegments, 

 each segment bearing a few black hairs on either side of the raised 

 mediodorsal golden-coloured hairs, and, laterally, a small black supra- 

 spiracular, and another subspiracular blackish tuft ; the abdominal 

 incisions, velvety-black, with bluish-white spots running longitudinally 

 dorsally, and on either side subdorsally ; the venter very velvety, each 

 segment showing more or less distinct traces between the prolegs of a 

 reddish medioventral line ; the spiracles almost hidden by hairy coat, 

 small, oval, pale, with blackish-red rim. The true legs brownish with 

 black claws ; the prolegs reddish with black hooks (Tutt). Reaumur 

 notes (Afemoires, i., p. 85) the peculiar arrangement of the hairs, by means 

 of which half the hairs from the lateral tubercles tend to be elevated, and 

 the other half depressed, with this peculiarity that part of those that are 

 elevated are applied against the body of the larva, and surround it, whilst 

 the others are more raised and pass the centre of the back, when those on 

 one side meet those arising from the opposite side. Newman thus des- 

 cribes the larva : " Head hairy, scarcely as wide as the 2nd segment, 

 which has three wart-like protuberances on each side of its anterior 

 margin ; body almost uniformly cylindrical, the incisions of the 

 segments not distinctly marked, every part of the body being densely 

 clothed with soft hairs ; the hairs on the dorsal region tend towards a 

 mediodorsal line, thus forming a mediodorsal ridge or crest, which 

 extends the entire length. Colour of the head purplish-black, adorned 

 with orange markings ; the labrum and clypeus are pale, and a pale 

 stripe extends from the latter to the epicranium ; colour of the body 

 intense velvety-black, with three longitudinal dorsal series of small 

 snow-white spots, visible only on the incisions of the segments, and 



* The larva in 2nd stadium in some respects reminds one of Cosmotriche potatoria 

 in 1st stadium, and appears to be nearer this species than to Lasiocampa quercus 

 n this stadium, and to be also a more primitive form than the latter (Bacot). 



