AEGYEAMCEBA. 101 



A. simson in the United States is said to be a parasite in the nests of Xylocopa 

 virginica. 



2. Argyramoeba acroleuca. 



Anthrax acroleuca, Wiedem. Aussereur. zweifl. Ins. i. p. 311 1 . 



Anthrax gideon, Macq. (nee Fabr.) Dipt. Exot. i. 1, p. 64, t. 20. f. 11 ( $ ) ; Sehiner (nee Fabr.), 

 Eeise d. Novara, Zool. iii. Abth. i. p. 122 2 . 



Hab. Guatemala, San Geronimo (Champion). — South Ameeica 1 2 . 



There is no doubt, I think, that the species provisionally named by Wiedemann 

 A. acroleuca, upon a specimen in the Berlin Museum, is different from A. gideon, 

 Fabr. I have a male and two females from San Geronimo, Guatemala ; the male has 

 the end of the wings chalky-white, as described by Wiedemann, the female not ; the 

 abdomen of both sexes and the hairs upon it are altogether black. My specimens 

 differ, however, from the type, which I saw in Berlin, in having the boundary of the 

 black across the discal and the fourth posterior cells straight, and not concave, as 

 represented in Macquart's figure. Both Macquart's and Schiner's specimens belong to 

 A. acroleuca. I do not understand what Sehiner means when he says that the present 

 species, with A. propinqua, Schin., and A. hictuosa, Macq., form a separate group, 

 distinguished by the position of the small cross-vein ; I do not perceive any such 

 peculiarity in my specimens. The suture on the antennal style is remarkably distinct 

 in this species, and the distal portion of the style cut off by it is much shorter than half 

 the proximal portion. There is no stump of a vein on the knee of the second vein ; 

 that on the fork small. 



3. Argyramoeba ? 



Hab. Guatemala, El Tumbador 2500 feet (Champion). 



I have a single specimen, which is exceedingly like A. acroleuca in general appear- 

 ance, shape, and colour, but it has long white hairs on the sides of the proximal half of 

 the abdomen ; the black on the wings encroaches slightly on the second submarginal 

 cell and, within the first posterior cell, reaches a little beyond the discal ; this makes the 

 hyaline sinus within the black appear deeper ; the distal portion of the antennal style, 

 cut off by the suture, is longer than half the proximal portion. This must be a distinct 

 species, but can hardly be A. gideon. The stumps of the second and third veins are as 

 in A. acroleuca. 



4. Argyramoeba analis? 



Anthrax analis, Say, Compl. "Wr. ii. p. 60 ; Wiedem. Aussereur. zweifl. Ins. i. p. 313. 

 (?) Anthrax georgica, Macq. Hist. Nat. Dipt. i. 406; Dipt. Exot. ii. 1, p. 68, t. 21. f. 11. 



Hab. Canada and United States. — Mexico'?; Centeal Ameeica'? 



