AMERICAN DIPTERA. 237 



States. I believe that it is Macquart's Dasypogon dimiatus, 

 hitherto known from Mexico. The following description is 

 made from this single specimen, which is in good condition. 



9- — Length about 20 mm. — Polished black, similar to cruciatus, but 

 the bloom of head and thorax is wholly grayish, while that of the 

 abdomen is only slightly golden, more nearly gray, and confined to 

 the first five segments. The wholly black antennae differ from those 

 of cruciatus in that the third segment appears longer, and the terminal 

 segment only about one-half as long. In cruciatus the thoracic dorsum 

 appears devoid of bloom except on the lateral margins, humeri and 

 the four small golden spots on the outside of the indistinct median 

 stripe, two before, above the humeri, and two on the transverse suture. 

 In this female the bloom covers the entire dorsum except the broad 

 median and the lateral stripes, each lateral stripe being greatly ab- 

 breviated anteriorly and narrowly and indistinctly bisected along the 

 transverse suture, thus appearing as two oval spots; the anterior 

 spot being narrowly separated from the median stripe by a line of 

 grayish bloom which appears more brownish along the middle of the 

 spot, the posterior spot of each stripe being confluent with the median 

 stripe, thus leaving the posterior portion of the dorsum, except on the 

 sides and narrowly before the scutellum, bare. Face, front, occiput, 

 pleurae and coxse wholly grayish pruinose; scutellum rather thinly 

 grayish pruinose, more densely so on the posterior margin. In 

 cruciatus each of the abdominal segments bears a golden pruinose 

 posterior cross-band; in this specimen the bands are present only on 

 segments 1-4, and possibly on segment 5; the remaining segments 

 wholly black. Unlike cruciatus, the bands are produced narrowingly 

 along the sides and nearly reach the anterior margin on segments 3 

 and 4. On the posterior lateral angles of segment 5 is a grayish spot. 

 Proximal portion of the venter wholly grayish pruinose; the venter of 

 the last five segments polished. Legs black, all the femora at base 

 and tip, more or less broadly, reddish; the front and middle tibiae and 

 their tarsi reddish-yellow; the hind tibiae and tarsi black, the basal 

 half of the tibiae reddish. Wings yellowish-brown, much darker on 

 the basal half before the basal cells; all the submarginal and posterior 

 cells broadly open, anal cell closed on the margin. 



This is a more pilose species than cruciatus; the entire pile 

 and bristles of the body are sordid white. In cruciatus the 

 bristles of the thoracic dorsum and scutellum are but weakly 

 developed, as is also the pile of the mesopleura and sterno- 

 pleura; here they are well developed and the pile upon the 

 pleurae is much longer and denser, longer also is the pile of 

 tergum and venter of the abdomen. 



TRANS. AM. ENT. SOC., XXXV. JUNE, 1909. 



