72 



was a modified form of the common O. bilobus, Fah., that I omitted it without hesi- 

 tation ; and I think it not improbable that many mimetic forms, especially among the 

 Lepidoptera, are but cases of dimorphism, in some instances perhaps dependent on 

 second broods. In another direction it shows that characters relied on as of the 

 highest generic importance are in some cases riot even of specific value." 



A conversation on the subject of" dimorphism" ensued, in which Prof. Westwood, 

 Mr. Waterhouse, Dr. Wallace, Rev. Hamlet Clark and Mr. Pascoe took part. Prof. 

 Westwood recollected no instance of dimorphism in the antennae, though instances of 

 dimorphism in other parts, as e.g. the mandibles, had for some lime been known ; it 

 was not uncommon in insects which possessed a remarkable development, in the male, 

 of some particular organ {e.g. among the Lucanidse, Onthophagi, &c.), to meet with 

 specimens, in other respects of the male form, but which had that particular organ 

 reduced to the female form. It had been suggested in Kirby and Spence that such 

 specimens might be neuters ; but Prof. Westwood regarded them rather as specimens 

 whose full development had by some means or other been retarded and left incom- 

 plete. 



Mr. Pascoe considered that there were many forms differing only in a single 

 character from the characters of the male or female of well-established species, and 

 that such were not entitled to rank as species or even sub-species, but were in fact 

 only a third form. 



Mr. Waterhouse thought that, in the division of insects to which reference had 

 been made, it was the rule that three forms existed — the normal male and female, 

 and the third intermediate, neuter or dimorphous, whatever its proper designation 

 might be. 



The President exhibited a monstrosity of Chrysomela Bauksii, captured last sea- 

 son ; it had the extremity of the right hind leg cleft into three distinct members, thus 

 giving it very much the appearance of a bird's foot. 



The President also, after referring to an exhibition made by him at the previous 

 (March) Meeting of the Society, exhibited a living specimen of Endophloeus spinosu- 

 lus, Latr. The insects, which had been captured by Mr. Turner in the New Forest, 

 proved, ou further examination, to be the true E. spinosulus. 



Mr. Smith also exhibited what had been sent to him by Mr. Turner as the larva 

 of Endophleeus, but which, in Prof. Westwood's opinion, was the larva of a Musca. 



Mr. C. Fenn exhibited a specimen of Laphygma exigua, beaten from sallow- 

 blossoms at Lewisham, on the 24th of March last. 



Note on Varieties. 



Mr. Fereday exhibited some specimens of the genus Taeniocampa, and read the 

 following observations on " Varieties," suggested by the exhibited specimens: — 



" Al the Meeting of this Society held in August last year, two specimens of Lepi- 

 doptera were exhibited by me, which were pronounced by the more learned and expe- 

 rienced of the gentlemen then present to be varieties of Taeniocampa munda. Both 

 specimens were taken near Croydon, the one (a male) on the 29th of March, and the 

 other (a female) on the 6th of April last year. I did not feel at all satisfied of their 

 being specimens of T. munda, and it was on that account they were exhibited. There 

 seemed to me to be a peculiarity in their form, colour and general appearance, which I 

 could not reconcile with any variety of T. munda known to me ; and it is rather a singular 



