THE ENTOMOLOGIST. 203 



fore wings, actually larger in the small insects from the Isle 

 of Man than in the large English ones, the variation from 

 the typical form being thus exactly the reverse of what 

 occurs in the Corsican subspecies Ichnusa, in which these 

 spots are altogether wanting. Whether some accidental 

 causes has dwarfed the insects, or that we have here a dis- 

 tinct insular variety, and the opportunity, as it were, of 

 watching the origination of a new species, future inquiry 

 must decide. Zygcena Filipendulae also occurs in a very 

 dwarfed condition : this I have observed both in 1867 and 

 1868, and the specimens exhibited are certainly the ordinary 

 condition of that insect in the island. I hope entomologists 

 who may visit the Isle of Man will collect other common 

 species found there, as well as the rare ones for which it has 

 become celebrated, that a wider basis for generalization than 

 at present exists may be obtained." 



Mr. Smith inquired whether Vanessa Urticae was always 

 thus dwarfed in the Isle of Man, or whether the sinallness 

 was one of the effects of the peculiarly hot season of 1868 ? 

 He believed that during the past season many Hymenoptera 

 had been observed in a dwarfed condition. 



Mr. J. Jenner Weir had noticed that the common white 

 butterflies of the past season were unusually small. 



Prof. Westwood remarked that the diminutive size might 

 perhaps be due to the heat, and the consequent rapiditv of 

 development of the insects, which remained a shorter time, 

 and therefore ate less, in the larva state. 



Mr. R. L. Davis (who was present as a visitor) mentioned 

 that he had a number of pupae of Smerinthus ocellatus of 

 very small size : the larvae had scarcely attained more than 

 half their usual growth when they were driven into the pupa 

 state by the frost destroying their food. According to his 

 experience, scarcity of food was generally the cause of small- 

 ness. During the season of 1868 he had preserved for the 

 cabinet, larvae of about sixty-five species of Lepidoptera, 

 most of which (including some of the diminutive Smerinthus 

 ocellatus) were exhibited. 



Mr. S. Stevens exhibited a moth from the British collection 

 of the late Mr. Desvignes, ticketed '^ immorata, Hub.,'''' which 

 it was suggested was an extraordinary variety of Strenia 

 clathrata. 



