210 THE entomologist's record. 



was not clear to the exhibitor whether the larvse had fed upon the 

 wood, or had simply excavated the cavities which were apparent in the 

 interior of the bowl for the purpose of pujjating. It was genei'ally 

 considered that the larva of D. vidpinus excavated the wood for the 



purposes of pu])ation, and not for food. On March 2Uth, Mr. H. 



St. John Donisthorpe exhibited a living female of Dijtiscus marginalls 

 with elytra resembling those of the male insect. Dr. Sharp said he 

 had seen this form before, but that it was very rare in this country, 

 though abundant in some other parts of the Pala^arctic region. Professor 

 Stewart asked if the genitalia had been examined. Mr. Champion 

 stated that Mr. J. J. Walker had collected several females of an allied 

 species {Dyfi>^ens drcumflexm) at Gibraltar with elytra resembling those 

 of the male. Dr. Sharp exhibited sijecimens of Brenthm anchorar/o 

 from Mexico showing extreme variation in size. He remarked that 

 the males varied in length fi'om 1U| mm. to 51 mm. ; the female from 

 9^ mm. to 27 mm. In the male the width varied from 1 ^ mm. to 4 mm. 

 Mr. Blandford commented on the difficulty of mounting minute Lepi- 

 doptera, Diptera, Neuroptera, etc., and exhibited samjdes of strips of 

 material which he had found most suitable for the purpose of staging 

 minute insects. He said his attention had been called to this method 

 of mounting by the receipt of specimens from Dr. Fric of Prague. On 

 examination of the material he found it to be a fungus, Polyporas 

 betulinus. He stated that Lord Walsingham had expressed his satisfaction 

 with this material, and had sent him specimens, similarly mounted, 

 from Zeller's collection. Mr. McLachlan remarked that he thought 

 the material exhibited preferable to artichoke pith, which had been 

 used for a similar purpose. Mr. Goss exhibited a species of Mantid, 

 Pseudocreohotra loahlbergi, received from Captain Montgomery, J. P., of 

 Mid-Ilovu, Natal. He said he was indebted to Mr. Chamjjion for 

 determining the species. Mr. Merrifield read a paper entitled " The 

 results of Experiments made last Season on Vanessa c-album and Limenitis 

 sibylla." This was illustrated by an exhibition of specimens of L. sibylla, 

 and a long series of V. c-albnm, to show the effects of temperature in 

 producing variation. Dr. Dixey said that many of the forms of 

 V. c-albnm. exhibited reminded him of V. c-aureum, a Chinese species, 

 which he believed to be the oldest form of the genus. He thought 

 that much of the variation shown in this series of specimens was due to 

 atavism, and was not altogether attributable to the effect of temperature. 

 Mr. Barrett said he was interested to find that one of the forced forms 

 of L. Sibylla was similar to a specimen he had seen which had emerged 

 from the pupa during a thunderstorm. In connection with Mr. 

 Merrifield's paper Mr. F. W. Frohawk exhibited a series of 20U speci- 

 mens of V. c-album bred from one female taken in Herefordshire, 

 in April, 1894. The series consisted of 105 males and 95 females, and 

 included 41 specimens of the light form, and 159 of the dark form. 

 Professor Meldola said that he was glad to think that the subject 

 of Seasonal Dimorphism, which had been first investigated sytema- 

 tically by Weismann, was receiving so much attention in this country. 

 He was of opinion that the results hitherto arrived at were quite in 

 harmony with Weismann's theory of reversion to the glacial form, and 

 all the evidence recently accumulated by the excellent observations of 

 Mr. Merrifield and others went to confirm this view as opposed to that 

 of the direct action of temperature as a modifying influence. 



