NOTES ON THE GENUS EUPITHECIA. 207 



to treat the forms (in Britain) as one species or as two; although, 

 for my own part, I consider that two forms co-existing within the 

 same area and maintaining separate life-cycles are better called 

 "species," and may, in the absence of evidence to the contrary, 

 be assumed to have passed beyond the stage of inter-crossing. 

 We must not forget, moreover, that the descriptions given by 

 Crewe and Westwood (Ent. Ann. 1863, pp. 116-121) indicate 

 wide larval divergence, although the German innotata larva 

 is also excessively variable. A good summary of the descrip- 

 tions and the literature will be found in Hofmann's ' Raupen,' 

 edition 1893, pp. 265-6. Rossler was the first to record finding 

 the larva of innotata on sloe (Wien. Ent. Monats. viii. 131), and 

 in 'Die Schu]3penfliigler ' (p. 195) he gave a longish note 

 summarizing what was then (1881) known in Germany of larval 

 food-plants, times of year, &c., and concluding that fraxinata 

 (bred in June or later from larvae occurring in June on ash, sloe, 

 whitethorn, mountain ash, flowers of dog-rose, &c.) was the 

 second brood of innotata, and tamaiisciata, Frr. (on Myricaria 

 fjermanica and Tamarix gallica), a dark southern form of the same. 

 Bohatsch followed (Wien. Ent. Zeit. i. 163) with a note sup- 

 porting the same contention, and recording the breeding of the 

 fraxinata form in August (as a second brood) from larvas on buck- 

 thorn and oak ; and in the same periodical (iii. 296) he recorded 

 that Habich had bred, between July 15th and August 15th, this 

 same second brood form from part of a batch of hibernated 

 pupae of which the rest had emerged normally in the spring as 

 typical innotata. Habich himself confirmed this some years 

 later (Stett. Ent. Zeit. liii. 159), and added the record of a 

 farther experiment ; he obtained a pairing of bred imiotata in 

 the early spring, fed the larvae on rose leaves, and got them full 

 fed by the end of April, the imagines appearing irregularly 

 through the months of May, June, July, and August, nearly 

 half of the total number in the last month. They were 

 smaller and lighter than typical innotata, and their larvae were 

 somewhat more slender, and in a few cases almost unicolorous 

 green. 



In the meantime Dietze made some observations on the 

 different larval races of what he considered E. fraxinata (Stett. 

 Ent. Zeit. xxxiii. 197-9, xxxvi. 69-70), from which we learn that 

 he found no considerable differences between the Primus larvae 

 and those of the ash, but that there was a difference between the 

 eggs, both of which he describes (xxxvi. p. 70) ; he points out, 

 however, that he only had six freshly laid eggs of the ash race to 

 compare, and that the differences may have been peculiar to the 

 individual brood. Imagines reared from ash laid their eggs both 

 on ash and hawthorn, and I gather that the larvae (second brood, 

 August) accepted both, but their further history is not traced. 

 Dietze regards both forms as definitely double-brooded, and 



