4 MR. WALKER'S CATALOGUE OF DIPTEROUS INSECTS 



the abdomen wetted, and I placed them on some blotting-paper 

 until they were dry. On returning them to the water, two re- 

 mained underneath a floating piece of cork, and the hair being 

 now dry retained the pellicle of air which is ordinarily observed. 

 One of the two came out of the water, attached the cork to the 

 glass, and wove a web against the latter, against which it rested 

 about a quarter of an inch above the surface of the water After 

 remaining there about two days, it resumed its aquatic habits, and 

 like all the others formed its winter habitation. I have now no 

 fewer than ten which have formed their cells, in which they are 

 perfectly at rest, and evidently hibernating. 



The general habits of this interesting animal are well described 

 by De Lignac, De Greer, Walckenaer, and others, and an excellent 

 resume of the whole observations is given by the latter author, in 

 his ' Histoire Naturelle des Insectes Apteres.' 



Catalogue of the Dipterous Insects collected at Singapore and 

 Malacca by Mr. A. R. "Wallace, with Descriptions of New 

 Species. By Francis "Walker, Esq., F.L.S. 



[Bead January 15th, 1856.] 



Mr. A. E. Wallace, so well known for his natural-history re- 

 searches in the valley of the Amazons, and for the extensive and 

 valuable collections sent home by him from that portion of South 

 America, has now turned his attention to the eastern world, and 

 is actively investigating the natural history of the East Indian 

 Islands, after having spent some months on the Malay Peninsula. 

 A large portion of Mr. Wallace's entomological collections pass 

 into my hands, and being desirous of making his labours scienti- 

 fically useful, I have requested Mr. F. Walker, who has such an 

 intimate knowledge of the insects belonging to the order Diptera, to 

 draw up the following catalogue of the dipterous insects discovered 

 by Mr. Wallace at Singapore and Malacca. My object in so 

 doing is to establish a kind of starting-point for tracing hereafter, 

 when all Mr. Wallace's collections shall have come to hand, the 

 geographical distribution of the Diptera in the very interesting 

 portion of the globe which Mr. Wallace is now investigating with 

 such indefatigable zeal. Singapore and Malacca, at the extremity 

 of the Malay Peninsula, are well placed for carrying out the pur- 

 pose I have in view, being in connexion northwards through the 



