124 PROC. ENT. SOC. WASH., VOL. 23, NO. 5, MAY, 1921 



opaque; last tergite brown, polished, the deflexed terminal portion a very short 

 but broad triangle; legs paler distally, the tarsi yellow-brown. Length 1.3-1.6 

 mm.; antennae .19-. 23 mm. 



Type, a male, Plummers Id., Md., from flowers of Staphvlea 

 trifoliata, April 28, 1915, McAtee. (U. S. N. M.) 



Paratypes Great Falls, Va., May 21, 1917, McAtee; and with 

 same data as type. On this occasion the flowers of the bladder- 

 pod shrub from which they were collected were literally filled 

 with these little flies, many pairs of which were in copula. 



Rhegmoclema willistoni, n. n. 



The species published by Williston (Trans. Ent. Soc. London, 

 1896, p. 269, PI. VIII, fig. 26) as Scatopse pygmaea Loew 

 (Cent. V, 13) is not that species -(Melander, Bui. 130, Wash. 

 Agr. Exp. Sts., 1916, p. 14) hence the name Scatopse pygmaea 

 Williston was a homonym from the beginning. So far as the 

 writer is aware Williston's species has not yet been named, and 

 he is pleased to be able to name it for the late Dr. S. W. Williston, 

 who had in the highest degree that most admirable quality in a 

 systematist, the conscious purpose of aiding others in the study 

 of his specialty. What a contrast is this policy to the mon- 

 opolistic tendencies characterizing the work of some taxonomists, 

 but in the long run how much more profitable to science and 

 vastly more creditable to its exponent. 



A single specimen, now unfortunately lost, which seemed to 

 agree perfectly with Williston's description and figure was col- 

 lected at Dead Run, Va., May 5, 1915, by R. C. Shannon. 



ANAPAUSIS Enderlein. 

 Anapausis cismarina, n. sp. 



First section of costa : second :: 2 : 1; subcostal cell broad, anterior branch of 

 fourth vein interrupted basally; last vein only slightly curved. Color black, 

 shining, with a brownish cast especially on legs, halteres yellow brown. Length 

 1.98 mm., antenna .33 mm. Male genital segment with two hairy stylets, 

 transversely grooved (hence appearing segmented); preceding segment divided, 

 the ends produced posteriorly into prominent teeth, one each side of median 

 line; claspers with a strong tooth externally, which is sinuate on its concave 

 antero-exterior margin. 



Type, a female, Great Falls, Va., May 19, 1915, in flower of 

 Liriodendron tulipifera, W. L. McAtee. (U. S. N. M.) Allo- 

 type, same locality and date. 



ASPISTES Meigen. 

 Aspistes hartii Malloch. 



Beltsville, Md., May 2, June 9, 1915, May 25, 1919, McAtee. 



Actual date of publication May 14, 1921. 



