( viii ) 



Yachal of Argentat, France. The species is a common one ; 

 whether that cs,\le([ J'ulvi ventris in the British List is a variety • 

 of it, or a distinct species, is not yet finally decided. I have 

 handed the dissections to Prof. Poulton, for presentation to 

 the Hope Collection in Oxford. 



Mr. A. Bacot exhibited a number of specimens of Mala- 

 cosoma neustria x castrensis in various stages, including a 

 series of six S S and sixteen $ $ imagines reared during 

 1902 from one batch of ova laid by a $ Castrensis, which 

 had been mated with a S JS'eustria, and two 5 $ reared from 

 another batch of ova the result of a similai' cross ; also blown 

 larvte of hybrid parentage, and twigs showing attempts at 

 ovipositing on the part of $ ? hybrids that had paired with 

 hybrid $ $ oi the same brood ; also a series of M. Xeustria, 

 M. Castrensis and the hybiid moths reared during 1901 for 

 comparison. He said that the larvfe of the 1902 broods, as 

 stated in the Society's Proceedings for June 4th last, exactly 

 followed those of the previous year in respect of their division 

 into " forwards" and "laggards," the former again producing 

 only females, and the latter males. By forcing the pupte of 

 the laggards it was found possible to synchronize the emer- 

 gencies this year, and pairings between the hybrid moths 

 were obtained. The females attempted egg-laying, adopting 

 the position and motions of normal females of Castrensis, but at 

 each opening of the ovipositor they produced only the small drop 

 of cement which accompanies the egg in the normal oviposition 

 of the parent species, resulting in a more or less perfect spiral 

 band of cement upon the twigs. The length of time occupied 

 in producing this result was about the same as that required 

 by M. Castrensis ? for depositing her normal batch of eggs, 

 which are laid at the rate of about eight or nine a minute. 

 Pairings or attempted pairings were also obtained between 

 the hybrid males and females of both the parent species, but 

 only a very few eggs were laid by these females, who subse- 

 qviently recommenced calling. Perhaps the most interesting 

 feature of the exhibit was the great variability shown by the 

 specimens comprising the larger of the 1902 broods compared 

 with the remarkable uniformity of the h} brid moths reared 

 during the previous year. Such uniformity appears the more 



