LASIOCAMPA QUERCUS. 65 



adds that viburni is a most marked and constant variety, and very 

 probably a distinct species. 



j]. ab. roboris, F. J. A. D.,* " Bork. Rhein. Mag.," i., p. 362 (with 

 reference to Esp., " Schmett. Eur.," pi. xiii., figs. 2-3) (1793); Schrank, "Faun. 

 Boica." ii., 1, pp. 275-276 (1801) ; Germ., "Bomb. Spec," p. 47 (1812) ; Sordelli, 

 " La Farfalle," p. 121 (1885); Kirby, "Cat.," p. 828 (1892); Auriv., "Iris," 

 vii., p. 150 (1894); Tutt, " Ent. Rec.," xiii., p. 113 (1901). Quercus, Esp., 

 " Schmett. Eur.," hi., pi. xiii., figs. 2-3, p. 84 (1783 . — Phalaena Bombyx quercus. 

 Alis reversis ferrugineis : fascia flavo punctoque albo. Linn., no. 25 ; Esp., tab. 

 xiii., figs. 2-6 ; tab. xiv., figs. 1-2 ; Rosel, tab. xxxva, fig. 1 larva, tab. xxxv^r, figs. 

 4, 5, 6 imago. Common everywhere in Oberhessen. Of quercus there are two 

 different races, which I am almost inclined to consider two different species, for 

 I have, on investigation, found that they breed true as Herr Esper has already 

 remarked, but in the larvae I found no difference in all the various stages of their 

 growth. Linne, it is clear from his description, knew only Esper's second race 

 (tab. xiv., figs. 1-2) ; should there, therefore, be two different species, this one must 

 retain the name of Bombyx quercus and might best be defined : Bombyx alis 

 reversis, maris saturate brunneis, fceminis ferrugineis : fascia flava punctoque albo. 

 The second species, or Esper's first race (tab. xiii., figs. 2-3), which is the commoner 

 in our district and throughout Hessen, may, on account of its relationship, be called 

 Bombyx roboris and might be defined as : Bombyx alis reversis, maris brunneis, 

 fceminis luteis : fascia flava postic^ diluta, punctoque albo. However, I leave 

 the decision of the question to more experienced entomologists f (F. J. A. D.). 



Westwood and Staudinger, and, following them, most recent 

 authors, have referred this varietal name to Schrank, and attached to 

 it a diagnosis that does not apply to Esper's figures (pi. xiii., figs. 

 2, 3), on which the original describer of the form largely, if not 

 entirely, based his diagnosis. Schrank himself also appears to have 

 studied Esper's figures, and makes the same references and uses 

 the same name as the original describer in Borkhausen's Rhein. 

 Mag., p. 362. Schrank's description reads as follows: "Sommer- 

 eichen Spinner, no. 1461. $ . The wings on both sides reddish- 

 chestnut-brown ; a white spot on the forewings — on the upperside 

 with a spot at the base|, and a band, yellow ; the underside with 

 the whole outer half yellow. 2 • The wings brownish - ochreous- 

 yellow, a white spot on the forewings, an obscure, anteriorly dark- 

 margined, almost straight, transverse line on all, whitish ; the rest 

 of the wing beyond the line paler. Bombyx roboris (Bombyx 

 quercus, Linn., 'Faun. Suec.,' no. 1106; Esp., vol. iii., pi. xiii., 

 figs. 2 — 6). Hab. : on oak, whitethorn, dwarf birch. Flight- 

 time : June. Very similar to the preceding species (quercus), and 

 the $ s hardly distinguishable at all. It is somewhat smaller than 

 quercus, and the 2 also somewhat more brownish-yellow. In the 

 $ the yellow band on the upper wings is, indeed, somewhat 



* Hagen attributes this article to Dr. A. F. A. Diel, we do not know on 

 what authority. Not only do the initials disagree, but the contemporary account 

 of Diel's writings (in Hamberger's Gel. Teutschl., edn. 5, Bd. ii., 1796) makes 

 no allusion to it (Prout). 



t Borkhausen, on p. 363, adds an editorial note: "I do not believe the two 

 races are different species. Only last summer I fed up a great number of larvae 

 which I found on alder bushes, and bred among them several females which were 

 very different in their ground-colour. Some were quite dark yellow, others as 

 dark as the females of the second race, whilst others might be regarded as inter- 

 grades between the two. They, therefoie, do not probably breed true. If one 

 is to regard merely the change of colour as of specific value, then one might also 

 make a separate species of the light ochre-yellow <? which Herr Geming possesses." 



% No mention is made of a spot at the base in the original description (supra). 



E 



