194 DIPTEEA. 



3. Promachus forfex, sp. n. 



Male. Face with a yellowish-grey pollen ; facial tubercle with black, rather scarce bristles, which latter, near 

 the oral margin, become pale whitish ; tufts on the cheeks white, not very dense. Antennae and palpi 

 black. Thoracic dorsum yellowish-grey ; dorso-central stripes dull brownish-black, the dividing line 

 between them distinct. Scutellum with yellowish-white hairs and black bristles. Halteres brownish- 

 red. Abdomen deep black above ; along each side a broad stripe of yellowish-grey pollen, beginning at 

 the end of the second, and ending at the end of the sixth segment; clothed up to the fifth segment with 

 scattered yellowish-white semi-recumbent hair (which interferes very little with the deep black ground- 

 colour, except on the hind margins of the segments, where it is more apparent, and that in a certain 

 light only) ; the hairs on the sides and on the venter sparse, erect, whitish-yellow ; venter brownish- 

 black. Forceps black, moderately shining; the lateral valves broader at the tip than at the base, trun- 

 cate ; the black central piece with a tuft of pale hair at the tip. Front coxse with a dense erect fringe of 

 long, white hair. Femora black, sparsely beset with short yellowish hairs on the proximal half ; tibiae 

 reddish-yellow, the extreme base and about one fifth or one sixth of the length at the tip black, beset 

 with short yellow pile and black bristles ; tarsi black. Wings with a slight brownish -yellow tinge, more 

 hyaline towards the anal angle ; the grey shadow in the first submarginal cell large, occupying the whole 

 disc of the cell; a distinct brown shadow at the end of the costal, marginal, and first submarginal 

 cells. 



Length 21-23 millim. 



Hal. Costa Rica, Irazu 6000 to 7000 feet (Bogers). Two specimens. 



This species very much resembles the Mexican P. quadratus, Bellardi (Saggio &c. 

 ii. p. 27, t. 2. f. 3), especially in the structure of the forceps. I have compared my 

 specimen with the type in Turin, and find that in the latter the surface of the abdomen 

 is much more densely clothed with greyish pile (and therefore does not appear nearly 

 so black), and that the facial tubercle bears a tuft of yellow hairs, among which there 

 are only a few black ones, &c. As the name quadratus must be changed, it being 

 preoccupied in the genus, I do not hesitate to describe our species under a new name, 

 leaving the question of the identity in abeyance. 



4. Promachus anceps, sp. n., ? . 



(?) Promachus fuscipennis, Bellardi (nee Macq.), Saggio &c. ii. p. 24, t. 2. f. I 1 ( ? ; the <? belongs 

 to a different species) . 



Female. Face greyish pollinose ; facial tubercle beset with black bristles ; some white bristles near the oral 

 margin ; cheeks with tufts of white hair, a row of which, mixed with some black bristles, beset the front 

 coxa?. Thoracic dorsum black ; its sides and the transverse suture greyish pollinose ; the line dividing 

 the dorso-central stripes almost obsolete. Abdomen deep black ; lateral and posterior margins of seg- 

 ments 2-4 margined with grey, the broadest part of these margins being in the posterior corners ; on 

 segment 5 the grey margin is not visible; the following segments are shining bluish-black, narrow, 

 and form the ovipositor-like prolongation; venter greyish; segments 1 and 2 and the venter beset 

 with soft, white hairs. Legs black, sometimes with a slight bluish reflection on tbe femora ; the bristles 

 black, but some sparse, soft, whitish hairs among them, especially on the femora. "Wings with a distinct 

 brownish tinge, more saturate along the veins ; the latter rather stout ; no grey shadow in the submar- 

 ginal cell. 



Length to the end of the fifth segment, 21-22 millim. ; with the ovipositor, 26-29 millim. 



Hal. \ Mexico (Salle x ) ; Panama, Bugaba 800 to 1500 feet (Champion). 



I have three females from the above locality, which agree quite well with the 



