AMERICAN DIPTERA. 311 



This is the first case I have seen where the hypopygium 

 is cleft on the left side. Hough says there is no cleft, but 

 I cannot think these specimens are otherwise than this spe- 

 cies, as they are very distinct in the markings of the abdo- 

 men. The females undoubtedly belong to the same species. 



37. P. flavomaeulatus Hough. 



d 1 . Front shining ; face silvery ; eyes narrowly separated ; occiput 

 brown or grayish, much more swollen above. Antennae brown, long 

 acuminate (Fig. 23); mouth parts yellow. Mesonotum subopake, 

 brownish ; scutellum black ; pleurae and metanotum hardly tinged 

 with gray ; humeri black ; halteres yellow. Abdomen long and slen- 

 der, shining, with only first segment cinereous ; lateral margins of 2-4 

 more or less broadly yellow ; otherwise black ; fifth larger, longer than 

 fourth with two dorsal indentations. Hypopygium shining black, as 

 long as, and nearly as broad as, fifth, triangular, assymetrical, with 

 cleft (Figs. 100-101); intermediate and ventral lobes small, black. 

 Legs slender, entirely yellow, even apices of tarsi ; without spines ; 

 apical and basal post-tarsal joints in proportion of 1:3.5. Wings 

 nearly hyaline (Fig. 184). Length and wings 4.4 mm. 



9. Similar. Front shining black, with lower portion silvery; 

 antennae (similar in shape to Fig. 22) brownish-black, with third joint 

 long, whitish acuminate. Mesonotum and scutellum brown pollinose ; 

 pleurae and metanotum faintly grayish ; halteres yellow. Abdomen 

 shining black, with faint hoary aspect ; first segment with a lateral 

 comb of four to five long brownish bristles. Ovipositor yellow, a little 

 shorter than its conical yellow base, stout and straight, hardly extend- 

 ing as far as the third segment, and is abruptly thickened at its junc- 

 tion with the base (Fig. 102). Femora more or less discolored basally, 

 subopake, with no distinct shining surfaces. Wings hyaline (Fig. 185). 

 Length and wings 4 mm. 



Described from Massachusetts. Before me are the follow- 

 ing, which I consider belong to this species : Highspire, Pa., 

 April (1 cf, coll. Banks, Figs. 23, 100-101, 184); Brookline, 

 Mass. (1 9 , Johnson, B. S. N. H., Fig. 102); Hampton, N. H. 

 (19 , Shaw, B. S. N. H., Fig. 185); both taken in May. 



It seems to me that these specimens without doubt belong 

 to this species, although Hough describes the hypopygium 

 without cleft, while this one has an opake hollow at apex. 

 This species is not to be confused with houghii Kert., which 

 has the stigma colored. The females are, in general form, 

 very similar to the males, in having the long slender abdo- 

 mens which are somewhat smaller basally than at apices. 



TRANS. AM. ENT. SOC, XXXVI. JANUARY, 1911 



