PHTHORARCHA. By L. B. Protjt. 3 



They appear in the late autumn or early spring and are often very abundant. The larvae are tree-feeders, 

 and the American species is reckoned among the injurious insects. The genus is very generally called by 

 the younger name of Anisopteryx Steph. 



A. aescularia Schiff. (1 a). Forewing pale brownish grey, darker dusted, with two dentate dark aescularia. 

 lines, the first bounded proximally and the second distally by ill-defined pale bands. Hindwing paler, with 

 prominent discal spot and weak dentate line. Under surface similar, rather paler. Usually very constant 

 in colour and markings, thoug occasionally unimportant darker aberrations are met with. — • In Japan and 

 S. E. Siberia represented by japonensis Warr. (la) which is somewhat ampler-winged, duller and less sharply japonensis. 

 marked, and differs structurally in having the discocellulars of the hindwing simple, with the second radial 

 from near the centre, whereas in aescularia they are biangulate, with second radial from near third. — urz- urzhumaria. 

 humaria Krulilc. from E. Russia is founded on a large, greyer specimen, with rather well-marked transverse 

 bands, and may perhaps prove to be a local race of either aescularia or japonensis. Larva pale green, 

 with faintly darker dorsal lines, yellowish subdorsal and spiracular lines and black spiracles. Recalls that 

 of Operophtera brumata, but is somewhat more slender, and easily known by the minute prolegs (or 

 processes) on the fifth abdominal segment. Feeds on most trees, with perhaps a preference for the common 

 elm. The (J sits by day on fences or tree-trunks or among dead leaves, the hindwings closely folded and the 

 forewings placed one over the other in a position almost unique among the Geometridae. It flies along hedges at 

 dusk and is strongly attracted by light. The typical form occurs chiefly in Central Europe, but extends to 

 Castile in the south-west, Scotland and southern Scandinavia in the north and Russian Transcaucasia in the 

 south-east. 



A. quadripunctaria Esp. (= aoeraria Schiff. nee Hufn., mellearia Scharfenh.) (lb) is of a browner colour quadn- 

 than the preceding species, the lines more indistinct, not white-margined, the hindwing whiter with the vundarut. 

 line obsolete. Larva greenish, with greenish-white dorsal and yellow lateral lines, feeds on various trees. The 

 imago occurs in the late autumn, and has a similar range to the preceding, but is wanting in Britain 

 and has no Oriental representative. The species has long been known as aceraria, but this is a homonym 

 and therefore untenable. 



A- tenuis Btlr. (3 a) Forewing of (J much stumpier than in the preceding species, and with some tenuis. 

 slight differences in neuration which would possibly justify the retention of the generic name Inurois, under 

 which Butler described it. Colour brownish- or purplish-grey, thinly scaled, the scheme of markings nearly 

 as in the two preceding, the postmedian line not, or not appreciably bent near costa. Discal dots somewhat 

 variable, usually very small, never very large or black. $ unknown. The species is only known as yet from 

 Japan, and its exact range there is not ascertained. The only specimens before me with precise data are from 

 Yokohama. 



A. membranaria Christ. (3 a) is closely related to the preceding, but the (J is on an average larger, memhra- 

 is considerably paler and has extremely prominent black discal spots on both wings, that on the forewing naria. 

 being very large. The $ possibly lacks the anal tuft of true Alsophila, but I have only seen one worn speci- 

 men. Occurs with the preceding species at Yokohama, but also in S. E. Siberia. 



2. Genus: !Plithorarclia Meyr. 



Nearly related to the preceding genus, distinguished by the narrower wings, the longer stalking 

 of the second subcostal of the hindwing, and especially the absence of median spurs. — Of the life-history 

 and habits nothing is as yet known. The single species has a limited range in Turkestan. 



Ph. primigena Stgr. (lb). ^■. forewing pale brownish grey, with two very faint dentate lines, the distal pHmigena. 

 incised near costa; cell-spot very weak, elongate; a brown streak from apex. Hindwing whitish, with obsolescent 

 cell-mark. Underside of forewing paler, costal end of distal line present. 5 apterous, with strong anal tuft. 

 Zerafshan to perhaps the Transcaspian region. Has been erroneously recorded by Leech from Japan, his 

 specimens having been really Alsophila japonensis. 



