150 DIPTEEA. 



specimen is somewhat injured), in the female black with black pile. Antennae black, the second joint very 

 small; third joint short onion-shaped, with a style twice the length of the incrassate portion, the bristle very 

 distinct. The black ground-colour of the thorax modified, without being entirely covered up, by short, 

 appressed, whitish hairs, which are denser and whiter on the pleurae ; scut el black, shining, with similar 

 hairs at the base only ; the macrochaetae on the sides of the thorax and on the scutel, although long, 

 rather weak. Abdomen black, the hind margins of the segments with distinct borders of whitish, 

 scale-like hairs; a tuft of longer white hairs on each side at the base. Male forceps remarkably 

 large, more than half the length of the whole abdomen, black, with a greyish pollen above, and soft, long, 

 scattered greyish hairs ; formed by the usual concave ventral plate, whose under surface is parallel to 

 the axis of the body ; seen from above, a deep fissure separates the two halves of the forceps, and a small 

 triangular piece is inserted between them. Halteres with a brownish stem and an ivory-white knob. 

 Legs black, beset with white, scaly hairs; the spinules on the tibiae very weak; the single spinules 

 on the outer side of the hind femora existing in other species replaced here by long, soft hairs. Wings, 

 hyaline from the very base ; no stump on the third vein. 

 Length, J , 5-6 millim. ; § , 6-7 millim. 



Hdb. Mexico, Northern Sonora [Morrison). 



A male and a female. I have but little doubt that the female belongs to the same 

 species as the male, as it agrees with it in many characters. 



A. peodes differs from its congeners in the large development of the male forceps, and 

 in the weakness of the thoracic macrochaetae and of the spinules on the legs ; it forms a 

 passage to the group of A. cy clops. 



BOMBYLIUS. 



Bombylius, Linnaeus, Fauna Suecica, 1758. 



1. Bombylius \ 6 $ . 



Hdb. Mexico, Northern Sonora (Morrison). 



This insect agrees quite well with B. atriceps, Loew, Centur. iv. no. 49 (Florida, 

 Virginia); but the scutellum and abdomen cannot be called "subnitida;" the front 

 femora are darker than "dilute lutei." I cannot decide without comparing types. 

 Numerous specimens. 



2. Bombylius \ e . 



Hdb. Guatemala, San Geronimo (Champion). 



Of the group of B. varius, Fabr., but smaller. Two males. 



The collection of Prof. Bellardi also contains two or three species of Bombylius^ 

 represented by one or two specimens each, in a bad state of preservation, and therefore 

 difficult to determine. Altogether this genus is but very poorly represented in the 

 collections before me. I find only three previously described species of the genus from 

 Mexico or Central America ; they are : — 



