Diptera 53 c 
Length, 2 mm. 
Type Locality: Nome, Alaska, August 21, 24, and 25, 1916 (F. Johansen). 
This species runs clown to perplexa Malloch in the paper previously referred 
to, but the colour of the legs, and the weaker tibial setulie are sufficient to warrant 
their separation. 
Aphiochaeta, sp. 
A female in poor condition appears to be distinct from the previous species. 
It has the hind tibial characteristics of that species as well as the bare meso- 
pleura, but in venation it agrees more nearly with alaskensis. It is not possible 
to satisfactorily describe the species. 
Locahty: Nome, Alaska, August 24, 25, 1916 (F. Johansen). 
BORBORID^. 
The larvae of this family live in manure, fungi, decaying vegetation, or, 
rarely, in putrid water in which there is decaying animal or vegetable matter. 
Several species are commonly found in marshy spots, and I have seen the 
imagines running upon the surface of stagnant water. In winter and early spring 
some species occur under dry grasses amongst dead leaves, and when disturbed 
jump violently about much as do springtails found in similar situations. 
There is only one species of the family in the collection. 
Leptocera Olivier. 
The species in this collection seems to be undescribed, 
Leptocera transversalis, n. sp. 
Female (alcoholic specimen). — Head yellow, ocellar triangle, upper half 
of occiput, greater portion of third antennal joint, arista, and clypeus black. 
Thorax black, lateral margins, centre of scutellum, and the pleural sutures 
l^roadl}^, yellowish. Abdomen brownish black dorsally, venter largely yellow. 
Legs black, trochanters, apices of femora, bases of tibiae, and* the tarsi yellowish. 
Halteres pale. Wings clear. 
Ocellar triangle large, sharp anteriorly, extending over midway from 
vertex to anterior margin of frons; orbital bristles three to four on each side, 
short but strong; interfrontalia with short setulose hairs, antennae rather large, 
third joint rounded apically; arista very much shorter than in typical Leptocera, 
not twice as long as antenna, thickened at base, distinctly tapered, microscopi- 
cally pubescent; vibrissa weak, genal bristle absent, the marginal bristles very 
short; cheek about one-third as high as eye. Thorax with numerous discal 
setulose hairs and only one distinct pair of bristles in dorso-central series, just 
in front of scutellum; posthumeral bristles absent; scutellum rounded, with a 
few very short discal hairs and four moderately long marginal bristles. Legs 
slender, without any distinct bristles, even on femora: hind tarsi with basal 
joint twice as long as second. Wing venation as in PI. Ylll, fig. 20, differing from 
that of most species of this genus in having the cross-veins very nearly directly 
below apex of first vein. 
Length, 2-5 mm. 
Type Locality: Pond at Collinson point, Alaska, June 13, 1914 (F. Johansen). 
Two specimens. 
This species differs so strikingly from others in Leptocera that it might be 
placed in a new genus, but as several workers are now engaged in revising the 
family I prefer to leave its removal from or retention in the genus to their decision. 
SYRPHID^. 
The larvae of the species in the present collection are either aphidophagous 
(Syrphus, etc.) or feed in sewage or decaying vegetable matter such as is found in 
swamp3' places (H elophilus) . 
