90 DIPTERA. 



rufous, rather than golden-yellow ; the abdomen (somewhat abraded) has scales of an 

 impure whitish colour, rather than silvery ; the white cross-band is on the second, not 

 on the first segment (which I suppose is a lapsus calami in the letterpress 1). 



2. Two (much better preserved) males from Northern Sonora have the spots on the 

 wings as large as in Van der Wulp's figure, but in both there is a spot in the anal cell, 

 connected, with that at the distal end of the fourth posterior cell : one of the specimens 

 only has a dot on the vein separating the second and third posterior cells ; the shadows 

 on the longitudinal veins between the submarginal cells, represented on the figure, are 

 hardly visible. The ground-colour of the wing is less greyish. The second abdominal 

 segment bears a broad white cross-band (a little broader on the sides than in the middle) 

 occupying the whole segment, except a margin posteriorly ; segments 5, 6, and 7 have a 

 dense covering of white, almost silvery, scales ; similar scales on the sides (in one of the 

 specimens even in the middle) of the fourth segment ; the interval between the white 

 cross-band of the second and the white covering of the apical segments (including the 

 posterior margin of the second segment) is occupied by yellowish scales ; all the segments 

 have a covering of black, semierect hairs, especially visible along the posterior margins, 

 and forming tufts on the lateral margins. This black pile is distinctly shorter here 

 than in the Guatemalan specimen. The venter is pale reddish, clothed with dense 

 whitish tomentum, and with pale yellowish erect, longer hairs, arranged in rows, which 

 appear distinctly from a side view. 



In the three specimens the antennal style is about two thirds the length of the third joint. 

 The female from Guatemala, on account of its greyish wings, with an unspotted anal 

 cell, is nearer to Van der Wulp's specimens (Venezuela) than the two males from 

 Sonora. Anthrax hela, Erichs. (Guiana), the type of which I have compared in Berlin 

 with one of our specimens from Sonora, also differs from them in the absence of the 

 brown spot across the anal cell ; nevertheless it struck me as being the same species. 

 Erichson's description is very short and even misleading, and cannot have any claim to 

 priority. If all the above-mentioned specimens belong to the same species (which I 

 deem very probable) it should be called H. albiventris (Macq. 1), Van der Wulp. 

 Whether the synonymy from Macquart holds good or not is an indifferent matter, 

 because there is an earlier Exopr. albiventris, Macquart, Dipt. Exot. ii. 1, p. 39 ; this is 

 an Exoprosopa and not a Hyperalonia, and, moreover, is a synonym of E. germari, Wied. 

 (comp. Schiner, Fauna &c. i. p. 56). Hyperalonia albiventris, Van der Wulp, represented 

 by a good description and a figure, may keep its name. 



2. Hyperalonia pilatei. (Tab. I. fig. 16, var.) 



Exoprosopa pilatei, Macq. Dipt. Exot. Suppl. i. p. 110, t. 20. f. 2 \ 



Four submarginal cells ; wings brown, except the apex and the posterior margin, often (but not always) pale 

 brown spots along the latter ; abdomen with a narrow white cross-band on the second segment, and with 

 silvery scales towards the tip, but without well-marked white or silvery spots. 



Length 16 millim. 



