1915.] NATURAI. SCIENCES OF PHILADELPHIA. 501 
parallel vertical ridges (see Plate XX, fig. 72). Ninth sternite exten- 
sive with a deep rounded emargination beneath, at the lateral end 
of this emargination a subtriangular to rounded lol)e with abundant 
short pubescence; on either side of the middle line is a sharp chi- 
tinized point, hidden or nearly so by the brush on the eighth sternite. 
Penis-guard elongate, the sides subparallel, the ventral face at about 
midlength ^vith a sharp point on either side, this point directed 
backward. Eighth sternite (see Plate XVII, fig. 29) with the 
caudal margin truncated or very slightly concave, with a brush of 
long yellow hairs on either- side, these brushes connected by a few 
scattered hairs in between. 
The female is similar to the male, but the antennae are short, the 
four basal segments mainly yellowish, the remaining segments a 
little darkened at the base, the apical segments uniformly dark 
brown. Ovipositor with the tergal valves very short, stout, blunt 
at the apex; sternal valves very short, high, obliquely truncated 
(see Plate XXI, fig. 84). 
Habitat. — Northwestern United vStates. 
Holotype, c^, Beaver Creek, Montana; altitude 6,300 feet; August 
1913 (S. J. Hunter). 
Allotype, 9 , topotypic. 
Paratypes, 14 cf's, 3 9 's, topotypic. 
The types are in the collection of the University of Kansas, para- 
types in the collection of the author. 
The specific name is that of a Siouan tribe of Indians of the 
Northwest. 
The only species \\dth which this fly might be identified is Tipula 
alia Doane {Annals of the Entomological Society of America, V, 44, 
1912) from Wyoming. There are many discrepancies between the 
descriptions of the two flies which lead me to believe that the prese^t 
form is a distinct insect; the head is not brown, but gray, with a 
narrow brown median stripe; the lateral prascutal stripes are 
indistinct; the wings show a distinct vitreous spot beyond the stigma; 
the size is larger and the cell 1st M. is not open (this open cell 1st m[ 
in alta is almost surely an abnormality of the type); the details 
of the genitalia are not as described for alta — the ninth pleurite is 
produced into a long spatulate point, the first appendage is an 
elongate, cylindrical, fleshy lobe, not small and spatulate; the 
inner appendage not at all as described for alta. 
Tipula dietziana sp. n. 
Coloration grayish; praescutum dull yellow with three brown 
