326 



Eyes distinctly separated; antenna more than one and a half times 

 as long as head and thorax together. Disc of mesonotum with very 

 short pale hairs closely placed ; 3-4 black settiL'e in front of wing- 

 base. Fore femora much thickened, the anterior surface with 2-3 

 irregular rows of short black thorns on almost their entire length; fifth 

 tarsal joint unspined ; tarsal claws equal, of moderate size, with a me- 

 dian tooth on the inner side. Third vein to five sixths the wing-length ; 

 first, to less than two fifths the length of third ; last section of first 

 slightly shorter than penultimate section of third ; media forking be- 

 fore cross vein, base of its posterior branch indistinct ; cubitus forking 

 proximad of cross vein. 



Length, 3.75 mm. 



Originally described from Pennsylvania. Early stages unknown. 



2. Heteromyia aldrichi, n. sp. 



Female. — Black, shining. Head black, antennje, face, and palpi 

 blackish brown. Thorax black, shining. Abdomen brownish black on 

 dorsum, ventrally yellowish, the segments of the apical half with a 

 brown spot on each side. Legs yellow, mid and hind coxje, apices of 

 middle femora and bases of their tibire, apical third of hind femora 

 and the whole of their tibiae, and apical two joints of all tarsi black- 

 ened. Wings clear, veins yellowish. Halteres whitish. 



Eyes separated by about a fifth the width of head; joints of basal 

 half of flagellum slightly longer than wide. Disc of mesonotum with 

 numerous rather weak hairs. Fore femora slightly tiiicker than hind 

 pair and with three spines on apical half of ventral surface ; fifth tarsal 

 joint without ventral spines; claws small, ecjual. Third vein ending at 

 about three fourths the wing-length ; first ending at two fifths the 

 length from base of third ; media forking before cross vein, base of 

 posterior branch indistinct ; cubitus forking very slightly beyond cross 

 vein. 



Length, 2.75 mm. 



Type locality, Moscow, Idaho (J. M. Aldrich). 



I have no hesitation in locating this species in Hcieroniyia because 

 of the presence of spines on the fore femora only, and because of the 

 small tarsal claws, which are similar throughout this group of the 

 genus. 



The species is named in honor of Professor J. M. Aldrich. who 

 kindly donated the specimen. 



A paratvpe from Berkley Hills. Alameda county. Cal.. April 11, 

 1908, submitted by Mr. Cresson, has the abdomen paler than the type, 

 but in other respects agrees with the above description. This speci- 



