104 



which, in the tense skin of the full fed larva can hardly be detected, are 

 very distinct — as do the other hymenoptera, the Chrysides before passing from 

 the larval to the pupal state spin a cocoon. 



C. nctjlecta having fed up in the cell built by O. spinipes and upon the 

 grubs stored up for the nourishment of the young wasp, which it thus supplants, 

 spins its cocoon in this empty cell, and as a perfect insect, emerges from the 

 cocoon by cutting off a lid. 



C. bidentata, on the other hand, having spun within the cocoon of 

 O. spinipes and shut off by a muror-like diaphragm the extra space not re- 

 quired for its smaller body, fii-st cuts away that diaphragm and then opens a 

 circular hole in the wasp cocoon tliroua;h which to emerge. 



Thus end the notes of Dr. Chapman, and I believe you will concur 

 with me in thinking that they exhibit many points of striking interest cal- 

 culated to enhance our admiration for Nature's marvellous works, at the same 

 time giving ample proof in the observer of a patience in investigation and a 

 zeal in the pursuit of knowledge which are the distinctive marks of the true 

 philosopher. He has enabled us to correct some errors fallen into last year 

 from lack of means at that time to test the accuracy of our observations. 

 ¥ov instance: In the plate which illustrates my paper in the last volume of 

 our Transactions the Chi-i/sis cocoon represented is described as that of C. irniia, 

 or C. bidentata, whereas actually it is that of C. neglecta. It is not made 

 in the cocoon of spinipes, but in the cell, the silk about the cocoon proper 

 having been spun by C. neglecta itself. 



Then again we gave a figure of Chrysis ignita which, though the com- 

 monest of the Chrysides, is but an occasional parasite on Odynerus spinipes, 

 whilst we omitted any representation of the two species which are its specially 

 appointed satellites. 



A box of the creatures themselves in erery stage of their existence, 

 and beautifully mounted, served to illustrate the paper. It was listened to 

 with great interest, and a vote of thanks to Dr. Chapman was cordially 

 awarded for his valuable contribution to science. 



PLATYSAMIA CECROPIA. 



Dr. Chapman sent a box of nearly full-fed larvse of this beautiful North 

 American Eombyx. They were very fine fellows, nearly four inches long and 

 as thick as a finger. They have a delicate blue green colour, with small yellow 

 and blue tubercles, those on the back of the third, fourth, and fifth segments 

 being red, and larger than the others. This larva spins a very large cocoon 

 of a strong coarse silk more adapted for carding than for winding purposes. 

 A few of the cocoons were exhibited, and also a pair, male and female, of 

 the moths, with an expanse of wing nearly six inches across and very wide 



