GUESTS AND PARASITES OF HALICTUS. I 5 



long spur three fourths the length of the metatarsus, hind tibiae with two 

 moderately long spurs, the outer one two-thirds as long as the inner, which 

 is nearly as long as that of the middle tibia. 



Wings hyaline with faint cinereous tinge, not brilliantly iridescent, the 

 heavy veins nearly black, reaching very nearly to the middle of the wing. 

 First vein but slightly bowed, third vein nearly straight, furcate, costal 

 bristles fine and short, thickly placed, distributed as follows : four proximal 

 to the humeral cross vein, twenty-two (double series) bordering the costal 

 cell, ten (double series) bordering the marginal cell, and six (in double 

 series) along the submarginal, /. e., the furcation of the second heavy vein. 

 Thin veins dark, the fourth longitudinal slightly flexed only at its extreme 

 base, so that the cell in front is slightly wider than the one behind, ending 

 a little closer to the wing-tip than the second light vein does, seventh vein 

 evident, extending into the wing-margin. Halteres whitish, their stem 

 dusky. 



Ma'e. Length, 1.75111111. Differs as follows : frontal bristles stouter, 

 abdomen smaller, genitalia not distinct, small, the central filament fleshy, 

 short, directed backward. Tibial setulse and the inner spur of the hind 

 tibiie reduced in size, ridge of the hind coxae large ; costal bristles not uni- 

 form, disposed thus : prehumeral four, twenty along costal cell, four along 

 marginal cell and four along the submarginal. The inner bristles are 

 minute, becoming larger at the third pair of the costal cell, and from thence 

 are much stronger than in the female. 



Described from several specimens, collected as described in the 

 previous account at Woods Hole, Mass., July-August. 



This species is related to agarici Lintner l but differs by the 

 longer bristles on the tibiee, longer front, four scutellar bristles, 

 etc. The habits also are quite different, as agarici feeds upon 

 decaying mushrooms. 



Phora rostrata sp. nov. 



Female. Length, 1.5-1.75 mm. Black, shining, legs more or less yel- 

 low, lower frontal bristles proclinate, third vein forked. 



Head shining black, especially smooth and polished on the front and 

 vertex. Front with the normal chaetotaxy except that there are only two 

 proclinate bristles at the lower edge. The front is also sparsely hairy 

 besides the large bristles. Median longitudinal groove and ocellar tubercle 

 unusually well-marked. Antennas black, with a distinctly plumose arista. 

 Proboscis piceous, very large and strongly exserted, as long as the head- 

 height. It is slender at the base where the rather small bristly spindle- 

 shaped black palpi are inserted, then much enlarged, swollen and bifurcated 

 at the extremity. The bifurcation is produced by a splitting of the apex by 

 a horizontal slit in the proboscis. Thoracic dorsum shining, hairy as usual, 



1 loth N. Y. Kept., pp. 399-406. 



