231 



veins dark brown, C, Sc, and R yellowish; macrotrichiae of veins dark brown. 

 Venation: Sci ending just beyond r;Sc2 far from the tip of Sci and only a short 

 distance beyond the origin of Rs; inner end of cell Rs lying proximad of cells 

 R4 and R&; vein 2nd A relatively long, the outer third gently sinuous, deflected 

 toward vein 1st A so that cell 1st A is narrowed shortly before its outer end. 



Abdominal tergites dark brown, with a relatively sparse vestiture of yellow 

 setae; sternites more grayish brown, the extreme caudal margins of the individ- 

 ual segments narrowly pale. Ovipositor with the valves horn-colored, the 

 tergal valves gently upcurved. 



Range. — Maine. 



Holotype, female, Southwest Harbor, Mount Desert, September 11, 1926 

 (Alexander). Paralopotypes, 50 females; paratypes, 4 females, Houlton, Aroos- 

 took Co., August 24, 1913 {Alexander). 



This very interesting species was taken in large numbers in a 

 small swale (described on p. 226) near Southwest Harbor. I at 

 once recognized the fly as being identical with a species I had 

 taken in northern Maine in 1913 and which had earlier (Cornell 

 Univ., Agr. Exper. Sta., Mem. 25, p. 781, 906-907, 967, 1919) 

 been tentatively identified as being Molophilus comatus (Doane). 

 In 1913 only a few specimens were secured and these all proved 

 to be females. With this knowledge available, a special and very 

 detailed effort was made to locate the male sex, but despite these 

 efforts all of the more than one hundred specimens seen proved 

 once more to be females. The very great abundance of the species 

 over a restricted area renders it improbable that the males had 

 appeared earlier and that their flight period was over. Working 

 on the possibility that there might be here a case of subapterism 

 in the male sex, I made a critical search on the moist earth of the 

 swale but without results. The condition of fully winged females 

 and subapterous males is very rare in the Diptera, as, indeed, 

 throughout the insect world. There remains the possibility that 

 the species is parthenogenetic, but such a condition could not be 

 proven without breeding the species. 



All records for Molophilus comatus (Doane) from New England 

 should be deleted and the present species added in its place. 

 The fly is readily told from all other eastern species of the genus 

 by the spotted wings. 



The holotypes. of the two new species described at this time are 

 in my collection, and paratypes are in the collection of the Boston 

 Society of Natural History. 



Massachusetts Agricultural College, 

 Amherst, Mass. 



