Mr. Westwood on new Dipterous Insects, 447 



copper by the foregoing results lost in seven days' immersion 

 46*2 and 45 per cent. 



In the first instance 1 was inclined to attribute the inde- 

 structibility of the unrefined copper in the acid partly to the 

 effects of the charcoal in the cementation, seeing that the effect 

 produced by that operation was much greater upon unrefined 

 than upon pure copper. Whatever advantages may belong 

 to the proper use of charcoal in the reduction and cemen- 

 tation of copper, (and I consider them not unimportant,) the 

 addition of a small portion of tin will be sufficient to account 

 for the superior resistance to waste which this alloy presents in 

 the muriatic acid, over that of the common refined copper of 

 this country. This incapacity to rapid oxidation which is 

 presented by the alloy of tin with copper, suggests many useful 

 hints to the artist and the manufacturer, of which advantage 

 has already been taken in forming ship-sheathing and other 

 articles. 



David Mushet. 



LXXII. Insedorum nonnullorum exoticatmm {ex Or dine Di- 



pterorum) Descriptiones. Atictore J.O^W^estwood, F,L.S» 4"^. 



[Continued from p. 281.] 



PHILOPOTA, Wied. Maculicollis, Westvf. Nigra ; thorace antice roa- 

 culis 2 minutissimis, alterisque 2 parvis ad basin alarum fulvis; abdo- 

 minis marginibiis tenuiter flavo notatis, segmentis terminalibus, sericie 

 subaurea tectis ; antennis nigris ; facie albid^ ; femoribus nigris, apice 

 rufis, pedum geniculis pallidis ; alis infumatis. — Long. corp. lin. 4|. Exp. 

 alar. lin. 1 1^. 



Habitat in Brasilia. *' Capta D. Swainson." In nms. nostr. 



Lepidophora, Westw. (Fam. Bombyliidcs,) 



Antennae capite triple longiores, squamulis obtectae, articulo Imo? 

 brevi, 2ndo longo gracili, 3tio breviori latiori, stylo apicali. Proboscis an- 

 tennarum dimidio brevior. Thorax valde gibbosus. Abdomen elongatum, 

 parallelum, cauda squamulosa ornatum. Alae farinosae, nervis ut in Cyllenia 

 dispositis. Pedes longi, graciles. 



Obs. Cel, Kirby et Spence hoc genus coramemorant libro " Introd. to 

 Ent." vol. iii. p. 646, pi. 12, f. 23, ubi Culicem cum Anthrace, &c., conjun- 

 gere credunt. 



Sp. 1. Lep. (Bgeriiformis, Westw. MSS. Ploas (Egeriiformis, G. R. Gray, 

 in Griff. An. K. pi. 128. 



Niger; thoracis lateribus flavo pubescentibus; abdomine maculis 6 latera- 

 libus flavis; alis infuscatis. — Long. corp. lin.5^— 6i. Exp. alar. lin. 11 — 14. 

 Habitat in Georgia Americae. — In Muss. Brit, et nostr. 

 Obs. Toxophora lepidocera Wied. congenerica videtur. 



Nemestrina, Latr. Rhynchocephalus, Fisch. FaUenia, Meig. t. 2. 

 Subg. 1. JVr^nw!, Macq. Palpi elongati, attenuati; antennarum stylo 



