. EEAX. 199 



Femora reddish, blackish-green on the under and posterior 

 side only. 



Male: nearly the whole abdomen silvery, with silvery -\ 



hair parted in the middle > 10. sp. ? 



Female : abdomen uniformly grey J 



Male: (?) . . -s 



Female : abdominal segments much darker in the middle > 11. sp. ? 

 than on the sides J 



1. Erax anomalus. 



Erax anomalus, Bellardi, Saggio &c. ii. p. 32, t. 2. f. 7 ( 3 ? ) x ; Williston, Trans. Am. Ent. Soc. 

 xii. p. 69 (1885) 2 . 



Eab. United States, Arizona 2 . — Mexico, Northern Sonora (Morrison), Cuantla 

 (de Saussure 1 ). 



This species is easily distinguished by the anomalous formation of the submarginal 

 cell (see the figure in Bellardi, I. c). The palpi are beset with yellowish hair and a 

 few black (rarely yellow) bristles at the tip. Second abdominal segment of the male 

 blackish anteriorly, its sides and a broad interrupted cross-band on the posterior margin 

 greyish-silvery; third segment blackish at the base, the rest silvery; segments 4-7 

 silvery ; the long silky-white hair, parted in the middle and combed outwards, begins on 

 the posterior half of the second segment and reaches the seventh. Hypopygium dark 

 reddish-brown, hairy. I have seen Dr. Williston's type ; Prof. Bellardi's specimens are 

 not in very good condition, and for this reason I am not certain of the specific identity, 

 which, nevertheless, is exceedingly probable. 



This must be a very common species. I have nearly a hundred specimens before me, 

 both sexes being represented in nearly equal numbers; all collected in Northern Sonora 

 by the late Mr. Morrison. 



2. Erax ? 



Eab. Mexico, Northern Sonora (Morrison). 



I have a single female from the above locality, with the same anomalous venation as 

 E. anomalus, but certainly a distinct species. The palpi have black hairs and bristles ; 

 the grey portions of the abdomen are of a purer whitish-grey; the black on each 

 segment is more intense, and the spots different in shape — less transverse, more like 

 inverted triangles with a rounded apex ; segment 6 is black, with narrow grey margins ; 

 the ovipositor is longer, equal to about four of the preceding segments ; the thoracic 

 stripes and other spots of a darker, purer brown. 



Erax computus, Macq., Dipt. Exot. i. 2, p. 117, t. 9. f. 9 (North America), has the 

 same venation as E. anomalus ; the male only is described, but it is not at all likely 

 that it belongs to the above-mentioned female. 



