HYDPTOMENA FITRCATA (lIPYSIPETKS SORPTnATA). 85 



SDnliclatti by l'\ibiicius, in 179 i; but there is, at least, one name 

 having a prior claim, and I cannot understand how it is that 

 Werneburg and Staudinger have ignored it ; it is accompanied by a 

 figure, and thus has even an advantage over the sonlidata of Fabricius, 

 of which merely a brief diagnosis is given. The name in question 

 is furcata, Borgstrom (in Thunberg's Dissertation's), and the date 

 1784. Borgstrom describes it as " alis cinereis, fascia simplici bifida 

 et trifida fuscis. Wings entire, rounded ; fore-wings cinereous, black 

 dusted and fasciated ; a slender fascia at the base, and another near 

 this, simple ; in the middle a broad fascia bifid towards the outer 

 margin (i.e., costa) ; at the apex a broad fascia projecting a trifurcate 

 branch," etc., etc. Of sonliilata, Fb., I'Jnt. Si/st., iii., Pt. 2, p. 185, 

 the diagnosis was : — " Phalfena seticornis alis virescentibus ; atomis 

 strigisque fuscis punctoque postico atro," and a careful, though brief 

 description, follows. This is mainly the same common sallow- 

 frequenting form as Hiibner's elutata (tig. 224). Guenee takes this 

 green form as the type, and gives three varieties : — (A) Entirely 

 green, without the dark bars ; sub-var. grey-blackish, also without 

 markings. (B) Hiibner, tig. 8S2, a curious and rare aberration. 

 Guenee includes here the specimens Avith the black bands very pro- 

 nounced, entire, and multiplied, and the central area paler. (C) 

 Hiibner, tigs. 381, 313. — The green ground-colour replaced by brick- 

 red, or sometimes by carmelite brown. This last is the " var. 

 fusen-undata, Don.," of Staudinger's Catahujuc, and Guenee has an 

 interesting note upon it. He notes its smaller size, and agrees with 

 Herrich-Schaefter, that it belongs to the bilberry-fed examples ; and he 

 then adds that Delaharpe considers this variety is artiticial, and may 

 be produced at pleasure by exposing the insect to an acid vapour ; 

 but he (Guenee) is satisfied that it is perfectly natural. He possessed 

 recently disclosed examples, met with under the same conditions as 

 ordinary green forms, and he points out that green lepidoptera, 

 especially those of an oZ//v-green shade, are peculiarly subject to these 

 colour changes — e.tj., Smerintlms tiliae. 



Staudinger, in bis Catalocfue, gives two named varieties : (1) " ab. 

 {etY.^)fusco-un(lata, Don. {Xat. Hist., xi., pi. 386, fig. 3), testaceous 

 or reddish, black banded." (2) "v. (et ab.) infmcata {/ tacetaria, 

 Frr., 640-2 ab.) al. ant. fere unicolor. infuscatis vel grisescentibus, 

 indistincta nigro-strigatis." Some of Staudinger's own Iceland 

 specimens, from which this variety was named, are in our collection 

 at South Kensington. None are so dark as our extreme British 

 melanic examples. 



In North America, where also the species appears to be common, we 

 find two other well-marked varieties, named by Packard ; they were 

 at first described by him as distinct species, and it seems to me not 

 improbable that one at least of them will really prove to be so. The 

 varieties in question are nxihilofaseiata. Pack., Prur. Bost. Soc, X. U ., 

 xiii., 398, Mono(jyaph, PI. viii., fig. 31 ; and albifasciata, Pack., Si.vtli 

 Eeji. Peab. Acad. Sc, 41, Monoijraph, PL viii., fig. 34. 



I have not been able to give sufficiently close and continuous study 

 to the details of variation to work out anything very satisfactory in this 

 connection at present ; but a few generalisations may perhaps be found 

 of some assistance : — (1) /S7;t'.— This varies a good deal, from con- 

 siderably uiider an inch to slightly over an inch and a quarter ; the 



