162 THE CANADIAN ENTOMOLOGIST 



dorsal face set with abundant spicules, the extreme apex a cylin- 

 drical spine; this appendage is bent slightly dorsad at its tip; 

 ventral appendage much longer and more slender from enlarged, 

 brown bases, with about six scattered teeth, at the apex bent 

 strongly ventrad. 



Habitat. — Colorado. 



Holotype. — cf , Platte Canyon. Colorado, altitude 10,000 feet, 

 August 26, 1915, (Oslar). 



Closest to M. paulus Bergroth (Alaska) but the hypopygial 

 details different, the dorsal appendage of paulus being shaped as 

 follows: short, bent slightly inward, the apex an acute point, the 

 surface of the appendage indistinctly denticulate; teeth on the 

 ventral appendage differently arranged. 

 Molophilus ursus, new species. 



Antennae of the male not elongated; general coloration dark 

 brown, the pronotal scutellum and the humeral angles yellowish; 

 male hypopygium short with the ventral hooks powerful, at about 

 mid-length enlarged and densely set with sharp, appressed spines. 



Male. — Length 3.5 mm.; wing 5 mm. 



Female.— hength 4.5 mm.; wing 5.8 mm. 



Rostrum and palpi dark brown. Antennae short, dark brown, 

 the flagellar segments oval-cylindrical with long, dark verticils. 

 Head brownish gray with long bristles. 



Pronotum light yellowish. Mesonotum dark brown, sparsely 

 gray pruinose; a conspicuous light yellowish triangle occupying 

 the humeral portions of the praescutum before the fovese. Pleura 

 dark brown. Halteres dark brown, the bases pale, the knobs 

 with pale, silky hairs. Legs with the coxae and trochanters yel- 

 lowish; femora brown, pale at the extreme base; tibiae and tarsi 

 dark brown. Wings dark-coloured; veins dark brown with long, 

 dark brown hairs. Venation : Cu\ — Mz moderate in length, a 

 little shorter than the basal section of ilfn-2; in one paratype 

 very much shorter, subequal to the basal deflection of Cu\. 



Abdomen dark brown, the segments ringed caudally with 

 paler; hypopygium short, stout, dark coloured; ventral hooks 

 short and powerful (Fig. 1,6), narrow basally, gradually enlarged 

 to about midlength, the ojjter angle thence produced outward as a 

 strong, black, slightly curved tip, the middle portion of the ap- 



