207 



" I am sorry to find that I have no exact memorandum of the 

 date when it was procured, but believe it to have been in the early 

 spring, about seven years since. 



" I am, yours faithfully, 



"J. H. GuRNEY." 



"P. L. Sclater, Esq." 



Mr. Gurney has at the same time forwarded for examination a 

 specimen of the Black-throated Diver (Colymbus arcticus) from the 

 coast of California, in fully adult summer plumage. Mr. Lawrence, 

 in his portion of the ' Report upon North American Ornithology,' 

 published in the ninth volume of the ' Pacific R. R. Report,' has 

 separated this bird from the ordinary Colymbus arcticus as a distinct 

 species, observing that, though he had not met with it in summer 

 plumage, its smaller dimensions, and, in particular, more slender and 

 weaker bill, seem to warrant his so doing. 



Comparing the Pacific example with a fine specimen of the ordi- 

 nary Black- throated Diver from these seas, kindly lent to me by 

 Mr. Leadbeater, we observe just these very differences. In plumage 

 there is none, or none worth mentioning. I am therefore hardly 

 inclined to think that the specific independence of Colymbus pacific 

 cus will ultimately be maintainable, knowing, as I do, that there is 

 considerable variation in size prevalent among European specimens 

 of the Black-throated Diver. 



7. On a new Lepidopterous Insect from Australia. By A. 

 W. Scott, M.A., Member of the Legislative Assembly 

 of New South Wales, Communicated by Dr. George 

 Bennett, Corr. Memb. 



(Annulosa, PI. LXI.) 



Hyphantidium sericarium. 



The silken web, portions of which are herewith transmitted, formed 

 by these small gregarious larvae, is so remarkable for its vast super- 

 ficial extent, the extreme evenness of manufacture» and the fineness 

 and beauty of the texture, that I have been induced to submit these 

 homely Lepidoptera, with their transformations, for publication in 

 the Proceedings of the Zoological Society, deeming the subject 

 worthy of notice and interest to the European entomologist ; — the 

 more so, as, after a careful and patient investigation of the families 

 closely related (the European examples of which have been so beau- 

 tifully illustrated and correctly defined by Hubner), I am led to 

 believe that the insects now before me are, in all respects, nonde- 

 script. 



Acting in accordance with this impression, I have formed a new 

 genus under the name of Hyphantidium : it will however rest with 

 the scientific naturalist at home, with his numerous books of refer- 

 ence and cabinet specimens, to determine this question and to correct 

 the error which I may thus possibly have fallen into. 



