T. D. A. COCKERELL. 193 



short ridjje; base of metathorax smooth anrt shining, with a median furrow; 

 tegiila?. hirge, reddish brown ; wings hyaline; nerviires dark brown ; second sub- 

 marginal cell narrowed about one-third ahove,^rs< recurrent nervure joining second 

 transverso-cubital, second joining third submarginal cell almost at its tip; legs 

 well developed, black, the tarsi becoming brownish ; pubescence of legs all white. 

 except on inner side of basal joints of tarsi, where it become orange-brown ; 

 spurs large, ferruginous; hind tibije swollen : abdomen rather elongate, shining' 

 with small sparse punctures ; hind margins of segments narrowly brownish ; the 

 whole surface with rather long, erect, yellowish white hair, only dense enough 

 to conceal to surface towards and at the apex: no well-defined bands; ai)ex 

 strongly bidentate. 



9. Length about 15 mm., but much broader, and thus more bulky than the 

 % . The pubescence is shorter and denser, with more of au ochreous tint, and 

 • covers the front and sides of the mesothorax. leaving, however, a shining and 

 sparsely punctured middle area. The wings are slightly brownish, and the first 

 recurrent nervure joins the second submarginal cell just before its end, while the 

 second recurrent meets the third transverso-cubital. Antenna entirely black, 

 hardly reaching to tegulse; hind portion of scutellum and postscutellumduUisb. 

 with close punctures; abdomen hairy, the pubescence appressed ; hind margins 

 of segments 2 to 4 with narrow white hair-bands; apex becoming fulvous; the 

 pubescence of the abdomen, and especially of the legs, is cream color rather than 

 white; brush on inner side of basal joints of tarsi dark, chocolate, with a slight 

 coppery tint. Claw and the large claw-joint entirely black ; tegula; piceous, with 

 a pale brown margin. 



Hub.— The I was taken on the campus of the New Mexico Agri- 

 cultural College, Mesilla Valley, in September (Ckll. 2408). It was 

 compared by Mr. Fox with Cresson's types and returned marked 

 "near denm:' The ? was taken at flowers of Splueralcea angusti- 

 folia at Whitewater, by the White Sands, New Mexico, October 6th 

 (Ckll. C 32.). I think it is safe to assume that the sexes described 

 are of one species, which may be known by its large size. Of the 

 New Mexico species D. megamorpha is most like D. australis Cr., 

 which I took at Santa Fe, June 20th, at flowers of Opontia. The 

 S (jf austrnlk will readily be known fi-om our insect by the struc- 

 ture of the hind tarsi, the more pubescent abdomen and the pubes- 

 cent mesothorax. I find I have also a S of i). australis, which T 

 took on July 9th at Whitewater, in Grant Co., New Mexico, a 

 locality far distant from the "Whitewater" cited above for the 9 

 of megamorpha. In tiie JVIe.silla Valley the common Diadasia is D. 

 diminata: it visits especially the flowers of Splueralcea angustifolia, 

 but also garden roses. Another species, D. enavata Cr {ursina), is 

 common in New Mexico, and may be taken in the Mesilla Valley, 

 in September, at flowers of Blgelovia ivrightii and Verbesina enceli- 

 oides, at Santa Fe, in" August, at flowers of Argemone, and has also 



TEANS. AM. ENT. SOC. XXV. (25) DKCEMBER. 1898. 



