236 ERNEST A. BACK. 



on the transverse suture yellow. Six unequal spots on the pleurae, a 

 spot above the halteres and on the hind coxae and the posterior margin 

 of the scutellum, also yellow or golden. Halteres reddish. Abdomen 

 polished black, tip in female sometimes reddish; each segment with 

 a broad golden cross-band on its posterior portion : venter of all the 

 segments except the first with a narrow golden band on the posterior 

 margin; the first two bands being partially bisected. Legs varying 

 from dark to pale ferruginous; the tibiae and tarsi often nearly straw- 

 colored. Wings varying from deep yellow and blackish to nearly 

 hyaline. The thoracic and scutellar bristles are very short and yellow; 

 the pleuras are nearly bare except for a patch of slight pile on the 

 mesopleurae and sternopleurae. Trichostical hairs long and rather 

 dense. The thorax and abdomen above are thinly clothed with 

 microscopic golden pile. 



The male differs from the female in being somewhat smaller; in 

 having the femora much darker, often black, and the general shade 

 of color markings. Two males in the collection of the Massachusetts 

 Agricultural College, and one male in the collection of Frederick Knab, 

 now at the Holyoke (Mass.) Public Library, have grayish markings, and 

 nearly all the other males which I have seen show a strong tendency 

 toward a similar color. The clothing of the male is much finer, and 

 upon the face nearly black. The lateral forceps of the genitalia are 

 quite prominent and clothed with long pile, as also are the terminal 

 segments of the abdomen below. 



Type. — Lost. 



Habitat.— North Saugus (July 15, F. H. Mosher), Holyoke 

 (July 10, F. Knab), Chicopee (July 1, F. Knab), W. Spring- 

 field (June 27, F. Knab), Montgomery (Aug. 7, F. Knab), 

 Mt. Tom (June 24, July 24, F. Knab), Amherst (June 23, 27, 

 30; July 6, 7, 8, 11, 12, 18; Aug. 5), Mass; New Haven 

 (June 23, W. E. Britton), Conn.; N. Y.; N. J. (June 8, July 

 10, E. Daecke); Pa.; Fla.; S. D.; Ark. 



This is a common species in Massachusetts and easily recog- 

 nized. Specimens are apt to become greasy, and thus ap- 

 parently lose their yellow markings. 



Ceraturgus dimidiatus. 



Dasypogon dimidiatus Macq., Dipt. Exot., Suppl. II, 51, 1847. 

 Dasypogon dimidiatus Walker, List, Suppl. II, 428, 1854. 

 Ceraturgus ? dimidiatus Bellardi, Saggio, II, 61, 1861'. 

 Ceraturgus dimidiatus Brauer, Wien. Ent. Zeit., II, 56, 1883. 



Mr. Samuel Henshaw has loaned me from the M. C. Z. a 

 female Ceraturgus from Dallas, Texas. It is new to the United 



