442 PROCEEDINGS OF THE NATIONAL MV8EVM vol. 43. 



Length, 5 mm. 



Two males November 3, 1906 (A. K. Fisher); 1 female, November 

 18, 1906 (W. L. McAtee), Plummers Island, Maryland. 

 Type.—Csit. No. 14834, U.S.N.M. 



Genus APOCEPHALUS Coquillett. 



TABLE OF SPECIES. 



i. The second pair of frontal bristles placed near the center of frona and almost directly 

 in line above the lower pair; ovipositor of female parallel-sided for about its 

 basal half, then narrowing into an obliquely pointed apical fourth. 



wheeleri, p. 442. 



The second pair of frontal bristles placed near the eye margins and not nearly 



straight above lower pair 2. 



2. Costa distinctly short of the wing middle, fringe long and sparse, fork of third vein 



indistinct; nearly coalescent with the apex of third, ovipositor of female parallel- 

 sided at base, contracted at tip third and with two bristle-like projecting organs 



at tip spinicosta, p. 442. 



Costa to about wing middle, fringe short and delicate 3. 



3. Ovipositor spatulate at tip coquilletti, p. 443. 



Ovipositor not spatulate at tip 4. 



4. Ovipositor about one-half as broad at its broadest part as long pergandei, p. 443. 



Ovipositor about one-third as broad at its broadest part as long similis, p. 444. 



With the exception of three males in the United States National 

 Museum collection none of the species are known in that sex. That 

 the last three species are closely allied there can be no doubt, but I 

 am quite certain they are not varieties of one species. 



APOCEPHALUS WHEELERI Brues. 

 Plate 38, figs. 1, 5, 9. 



The type-specimen of this species is in the collection. Quite dis- 

 tinct from any of the other recorded species. In this species the 

 arista is apical. 



APOCEPHALUS SPINICOSTA, new species. 

 Plate 38, figs. 2, 8, 11. 



A single specimen of this very pretty species standing unidentified 

 in the collection. In the position of the frontal bristles it resembles 

 the next three species, but in other respects it is very different. 



Description: Yellow; frons black, bristles as in pergaiidei Coquillett; 

 antennse yellow, third joint nearly round, arista dorsal rather 

 thick and short, not longer than frons ; palpi yellow, weakly bristled ; 

 thorax clear yellow, scutellum with only two apparent strong bristles, 

 abdomen brown, only the basal segment yellowish, very narrow, 

 second segment .the longest ; no distinct bristles except on the sixth 

 where they are very strong, ovipositor highly polished, parallel-sided 



