3500 Entomological Society. 



Mr. S. Stevens exhibited a fine series of Goliathus Polyphemus from Cape Palmas, 

 and of Callithea Sapphira, male and female, collected by Mr. Bates at Santarera, on 

 the Amazon river. 



The President read the following letter, addressed to him by Mr. Ainger : — 



" 2, Carlton Hill, Edgware Koad, 



" April 17, 1852. 

 " Sir, 



" I observe that at a recent meeting of the Entomological Society, you 

 read a paper of inquiry as to the best method of extirpating cock-roaches. 



" I have for many years, and in three different houses, used a plan which gets rid 

 of them more rapidly and more completely than any I have heard of. 



" In the kitchen hearth, within the fender, but at one side of the fire, I cut a hole 

 like that made in the street paving for a coal-plate. In this I place a basin holding 

 a little water (beer would perhaps be better), and into this the creatures fall by whole- 

 sale until they are nearly exterminated. During the day an iron plate covers the hole. 



" I am, Sir, 



" Your obedient Servant, 



" Alfred Ainger.'' 

 " J. O. Westwood, Esq." 



Mr. Douglas read the following note, translated and condensed from the ' Ento- 

 mologisehe Zeitung ' for April : — 



" On Lithosia depressa and L. helveola ; by Herr Schreiner, Weimar. 



" If we compare these two insects, and read the descriptions of the larva? by 

 Treitschke (Band x. pp. 164-5), we should feel quite convinced that they were dis- 

 tinct species ; but by observing them in nature, both in the larva and perfect states, 

 we may be quite certain that depressa is by no means distinct, but only the female of 

 helveola. 



" I would not lay much stress upon the fact that during many years' experience of 

 myself and others in this and other localities, not one male of depressa has occurred, 

 and just as little a female of helveola, although this is curious enough ; but I would 

 further mention that although I yearly rear a great many of both kinds from larva?, 

 which are not scarce in this neighbourhood, mingled together among the lichens upon 

 the common pine (Pinus picea), the result is the same. I believe, therefore, that I 

 am correct in putting depressa, hitherto accounted to be a distinct species, as the fe- 

 male of helveola ; and the following considerations bear out my view : — 



" 1. The antenna? of helveola are distinctly ciliated, in depressa, on the contrary, 

 they are setiform, and only when greatly magnified can a few very fine hairs be 

 observed. 



" 2. The larva? appear at the same time and on the same food, .and mostly together. 



" 3. They show no striking difference in form, colour, or marking, in these respects 

 not varying more than the caterpillars of most other species. 



" 4. The habit and pupation are the same. 



" 5. The period of development is exactly alike. 



" I must further remark that I indeed have not yet witnessed the coupling, because 

 it would seem to be very brief, and only to take place at night ; however, I have often 



