THE BRITISH LltARID MOTHS. 93 



square-ended, although this last mentioned character would be more 

 noticeable if the larva had been drawn soon after hatching, instead 

 of nearly full-fed in 1st skin. In its adult plumage the larva is 

 usually lemon-green, with strongly-developed dorsal tufts on the 1st 

 to 4th abdominal segments, and the incisions between these segments 

 all velvety black. A long pencil of pink hairs arises from the 8th 

 abdominal segment. 



(To he continued.) 



Some Notes on Oporabia autumnata, Bork. 



By LOUIS 13. TilOUT, F.E.S. 



Following up my very fragmentary notes on the dubious forms of 

 Oporabia, structurally related to /ili;/ratn)iiaria, and dealt with in the 

 Ento)n<)l(i;/i.st'.'< Record, vol. ix., pp. 815-818, as 2rt var. (?) addendaria, 

 and 26 var. (?) approximaria, I may say that a good deal of material 

 has come into my hands since my paper was written ; and, although it 

 does not definitely set at rest the question, " Have we a third species 

 of Oporabia.' " yet it is of suflicient importance to call for publication, 

 and is especially satisfactory as clearing up, and somewhat simplifying, 

 a very tangled piece of synonymy. 



As I proposed [torn, cit., p. 281), I obtained a good many specimens 

 of so-called dilutafa from the Continent, and found the true diliitata 

 and the suspicious-looking specimens, with angulated second line, to be 

 in about equal proportion. By the kind help of my usual referee, 

 Mr. F. N. Pierce, I was able to prove that the males of the latter 

 were structurally of the jilii/rainiiiaria type; in other words, that they 

 were perfectly distinct from dilutata. Amongst these was a specimen 

 of the whitish form which I mentioned as being "no doubt the 

 autumnata of Borkhausen," and, therefore, my suspicion and hope 

 were confirmed. It remains for me to point out my grounds for 

 accepting this form as Borkhausen's antwiniata (btaudinger only 

 quotes it with a query), and to claim the recognition suggested by 

 No. 28 of the " Merton rules " (Lord Walsingham and J. H. Durrant), 

 that " the decision of the author first dealing with the question shall 

 be accepted as final, unless his conclusions can be proved erroneous." 



Borkhausen (Xatun/. hhir. Schinett., v., p. 293 [1794] ) described 

 his autumnata as " Silberweisser, blassbraunstreifigter Spanner," as 

 being about the size of rluimnata, white with some gloss, with pale 

 brown lines standing in four groups, and forming, as it were, four 

 bands — namely, a single line at the base, then two close together, 

 then three together, finally again two, the commencements of these 

 lines on the costa being more strongly expressed ; as having some 

 little black strokes on the nervures, and a black spot in the third 

 band ; and as having been found in a birch wood in October. Now 

 it would hardly be too much to say that the definition of the insect 

 as " silver-white," would be sufficient for its determination, so 

 excessively rare are really white forms of dilutata. Probably nearly 

 every old diagnosis could be called in question if every possible and 

 abnormal colour-variation needed to be taken into account. But 

 Borkhausen does not leave matters here. On pp. 5G4-505, in a sup- 

 plement, he gives some further notes on the Oporabias, based (as ho 



