AET. 7 AMERICAN MUSCO'^'^ ^LIES IN VIElSriNrA MUSEUM AX.DEICH 23 



validity, never high in this group, depends on the absence of con- 

 necting forms in the particular small series under consideration. 

 Not having the genotype of Ctenophorocera at hand, I can express 

 no positive opinion of the genus, but I would put biserialis back in 

 Phorocera, vrhere Schiner described it. 



Front at narrowest 0.23 of the head width in male, 0,27 in female 

 at vertex. Eyes densely hairy, cheek 0.3 the eye height, head with 

 yellow pollen in male, gray in female; male without orbitals but 

 with a few extra bristles outside the frontal row (whence the name) 

 opposite the antennal insertion ; female with orbital- but with simple 

 frontal row; palpi j^ellow, obscured with rather dense dark hairs. 

 Cheek and a considerable space behind lower part of eye with black 

 hair. The row of hairs outside the bristles of facial ridge is but 

 slightly developed, no more than in several North American j^pecies 

 of related genera which I examined for comparison, 



Mesonotum gray (tinged with yellow in male) with four shining 

 black stripes. Chaetotaxy: acrostichal, 3, 3; dorsocentral, 3, 3; 

 humeral, 4 ; posthumeral, 2 ; presutural, 2 ; notopleural, 2 ; supraalar^ 

 3; intraalar, 3; postalar, 3 (1 large between 2 small) ; sternopleural,, 

 1, 1 (2, 1 in male, the lower small) ; pteropleural, 0; scutellum with 

 3 lateral, 1 small apical (broken off) and 1 discal. Scutellum dark 

 in ground color with only trace of lighter at tip, densely gray poUi- 

 nose with a darker spot on disk beyond middle. Calypters yellowish- 

 white. Abdomen black, densely gray pollinose, tessellated, more yel- 

 lowish in male and with indistinct reddish ground color at sides ; no- 

 discals except on fourth segment, which has dense yellow pollen in 

 female, golden in male. Second segment with one pair median mar- 

 ginals. Male with no patch of hairs on venter of third segment, but 

 with an oval area of very fine hair on the fourth segment below, ex- 

 tending nearly to the side and sharply differentiated there. 



Legs black, tarsi not long, but with slightly elongated claws and 

 pulvilli ; middle tibia with one bristle on outer front side ; hind tibia 

 ciliated in male, much less so in female. 



Wings subhyaline; fourth vein with rounded rectangular bend; 

 first posterior cell open not very far before apex; third vein with 

 2-3 hairs at base, other veins bare. 



Length, 8 mm. 



Not in National Museum. 



101. PHOROCERA CAERULEA Jaennicke 



Phorocera caerulea Jaennicke, Neiie Exot. Dipt., 1867, p. 382. 

 Ctenophorocera hlepharipus Beauek and Behgenstamm, Denk. Wien. Akad. 

 Wiss., vol. 58, 1891, pp. 342, 402. 



The locality as given in the original description was left in uncer- 

 tainty between Cape of Good Hope and Brazil, hence I asked to see 



