Dec, igis] TowNSEND : New Muscoidea. 227 



minute hairs on orbital edge, and seven downwardly-curved bristles 

 forming a row parallel with facialia. Cheeks rather over one half 

 eye-height. Cheek grooves restricted, short. .Several stronger bristles 

 on front portion of occipital area of cheeks. Sternopleurals, o : i : i ; 

 postsuturals, 3; preacrostichals, 2; postacrostichals, i front one, the 

 middle and hind ones showing as minute hairs. Two lateral scutel- 

 lars, the posterior one reaching to base of third abdominal segment; 

 a reclinate decussate apical pair, as strong as anterior lateral; two 

 weak erect approximated discals placed far forward. Wings longer 

 than abdomen, not broadened. Costal spine strong, erect ; a second 

 shorter one more or less appressed to costa. Third vein bristled to 

 small crossvein. Apical cell with petiole about as long as hind cross- 

 vein, petiole formed by third vein. Apical crossvein originating from 

 cubitus at obtuse angle, very faintly sinuate; cubitus without ap- 

 pendage. Hind crossvein straight, slightly nearer to cubitus than to 

 small crossvein, set at an angle of about 45 degrees to the hind margin 

 of wing, not parallel with apical crossvein. Tegula; large, subrounded, 

 front scale hardly one fourth the size of hind scale. Legs short. 

 Hind tibiae subpectinate, with about three long and seven short bristles 

 on outer edge. Metatarsi about twice as long as second tarsal joint, 

 except posterior pair which are one and two thirds times second joint. 

 Claws hardly as long as last tarsal joint. Abdomen elongate-oval, no 

 wider than thorax ; tip broadly subtruncate, its edge slightly concave ; 

 first segment with one lateral marginal macrochreta ; second with one 

 median discal pair, one median marginal pair, two lateral marginal 

 and one weak lateral discal; third with one median discal pair, one 

 median marginal pair, two lateral marginal and several weak mar- 

 ginal ; fourth well covered with strong ones. Hypopygium with 

 rather slender forceps. 



Polideosoma rohweri new species. 



Length of body, 5 mm. ; of wing, 3.75 mm. One male, Florissant, Colo- 

 rado, June 16, 1907 (S. A. Rohwer). 



Black. Head silvery pollinose; antennae and frontalia brown or blackish, 

 with bloom ; arista black. Beard white. Palpi obscurely rufous. Thorax 

 shining black, with faint bloom, showing three heavy broad vittae behind in 

 oblique view. Scutellum and abdomen shining polished black, without bloom. 

 Legs black with a brownish tinge. Wings clear. Tegulae watery-whitish. 



Holotype, No. 19568 U. S. N. M. 



Named in honor of Mr. S. A. Rohwer. 



