J. R. MALLOCH 153 



Limnophora tetrachaeta sp. n. 



Male. — Shiniiifi lihick. Thorax with faint pruinoscenfo. Abdomen with 

 dense brownish gray yjruine.seence, a fine dorso-eentral black vitta between 

 the bhick paired spots. Wings sHghtly grayish. Calyptrae obscurely yellow. 

 Halteres black. 



Eyes separated by almost twice the width across posterior ocelli; orbits 

 narrow, strongly bristled nearly to anterior ocellus; parafacial not as wide 

 as thiril antennal joint, slightly narrowed below; cheek about twice as high 

 as width of i)arafacial; setulae contimied above vibrissae about one-third 

 of the way to base of antennae; arista pubescent. Presutural acrostichals 

 strong, irregularly two-rowed; postsutural dorso-centrals four. Abdomen 

 narrowly ovate, thick; fifth sternite and hypopygium as in figures 19 and 2U. 

 Legs stout; fore tarsus longer than tibia, the latter with a median posterior 

 bristle; mid femur with a number of short bristles on basal half of antero- 

 ventral surface and some longer bristles on basal half of postero-ventral ; 

 mid litMa with at least one antero-dorsal bristle, the postero-dorsal and pos- 

 terior surfaces with one or two bristles each; hind femur with a complete 

 s(>ries of antero-ventral bristles, and some shorter bristles on basal half ot 

 jxistero-ventral; hind tibia with two antero-ventral, two antero-dorsal and 

 two or three postero-dorsal bristles, the latter very short. Length, 5 mm. 



Typc—d"; Blitzen Kivor, Oroo-on, July (>, 1906, [Illinois]. 

 Parati/pes. — 1 cf , topotypical; 1 cf, Bozomaii. Montana, July 23, 

 1915. 



There is a female specimen in my mateiial which appears 

 to l)(>lono; to this species. It has the frons one-third of the head- 

 \vitlth, each orbit with five strong bristles and a few short setulose 

 hairs, the abdomen shining, without distinct spots, the fore 

 til)ia with an antero-dorsal bristle at middle, and the hind fenuu' 

 with three long bristles at base on postero-ventral surface. The 

 costal thorn is much longer than in the male, and the last section 

 of fourth vein is less than twice as long as preceding section, 

 while in the male it is over twice as long. Locality, ]\l3''stic Lake, 

 Montana, July 24, 1902. 



Limnophora alticola s]). n. 



Male. — Differs from caroli in having the thorax much deeper black, with- 

 out distinct markings. The abrlomen is similarly marked to that of caroli, 

 the space between the dorsal s])ots being more or less filled in witli brownish 

 or fuscous. 



Eyes separated by width across posterior ocelli; interfrontalia almost 

 obliterated in front of ocelli; profile almost as in nhsnleta (fig. o3). Chae- 

 totaxy of thorax and legs as in caroli. Incision of fifth sternit(> not so clearly 

 wedge-shaped as in caroli, the base of the incision 1i-uncnt(Mi. 



THAXS. AM. ENT. SOC, XLVI. 



