84 



" In old and neglected specimens the pins become quite corroded by verdigris: to 

 prevent the occurrence of tliis, a method is used in Germany, of which I was informed 

 by Mr. Dohrn -. it consists in pushing the pin further through the insect than it is in- 

 tended to remain, covering the portion immediately below the insect with a solution 

 of gum arable, and then drawing back the pin, which, by the coating it has received, 

 is preserved from the action of the grease. The same principle has recently been ap- 

 plied in this country, by electro-plating the pins ; and it is likely to be of use for those 

 species in which the pin becomes corroded, and yet the grease does not much affect 

 the insect: but the expense of these pins will prevent their general adoption." 



Mr. Edward Sheppard said he had found the use of electro -plated pins check the 

 growth of verdigris in greasy insects. 



Mr. Edwin Shepherd said he had tried pins doubly-gilt, and yet in some instances 

 he found they were acted on by the grease of the insects. He thought that when the 

 bodies of insects rested on the paper they were more liable to become greasy than when 

 the insect was elevated on the pin, as in the continental method. 



Mr. Waterhouse said one great cause of greasiness was the placing insects in the 

 cabinet soon after they were captured. 



The President said that in the continental cabinets, where quicksilver was used, it 

 was confined to grooves in the bottom of the drawers. 



Captain Cox said that so long as he kept his insects in London none of them were 

 greasy, but having removed them into the country, near to a running stream, forty or 

 fifty of them have become greasy, and this effect he attributed to the moisture of the 

 atmosphere of the place. 



Mr. Jansou read the following two notes by Dr. H. Schaum, of Berlin: — 

 On Hetcrurrhina bicostata, Westwood. 



" Mr. Westwood has lately given, in the ' Transactions ' of this Society, New Series, 

 iii. p. 66, some details and a drawing of an African Heterorrhina, which he considers 

 to be the H. bicostata, published by me in the fifth volume of the ' Transactions,' p. 

 65. He asserts that the unique specimen described by me, is in Captain Parry's col- 

 lection, and that his drawing had been taken from that specimen. 



" I beg to state that this assertion is not correct, but that my specimen was from the 

 cabinet of the late Mr. Melly (as indicated by me 1. c. p. 65), and is now in the posses- 

 sion of his son. I mention this, because a comparison of Mr. Westwood's figure with 

 my description leads me to the opinion that the H. bicostata of Mr. Westwood is spe- 

 cifically distinct from the insect published by me. 



" The following differences seem to exist between the two insects : in the typical spe- 

 cimen of Heterorrhina bicostata of Schaum the thorax is unusually small ; the meso- 

 sternal part of the sternal process short; the four posterior tibiEe deeply sulcated inside ; 

 while in the specimen figured by Mr. Westwood the thorax is of the usual size, 

 the mesosternal process long, and the four posterior tibire without furrows on the 

 inside. Furthermore, the anterior tibice are simple in Mr. Melly's specimen, while 

 they are armed beyond the middle with a broad, though obtuse, tooth, in Captain 

 Parry's insect. On this last difference I lay, however, but little stress, as it may arise 

 from the two specimens belonging to different sexes. For, though Mr. Westwood 

 designates his specimen as a male, I am inclined to draw from his own words the con- 



