DESCRIPTION OF NEW SPECIES 165 



hairs not modified, although brownish in color and slightly denser than 

 on the preceding segments. 



Female. More robust, oblong-ovate; fifth ventral segment rather 

 long, only moderately broad and rather strongly rounded at apex. 



Measurements. Length (Types), 3.5-4.0 mm.; width, 1.3-1.4 mm. 



Holotype, male, and paratypes in my own collection ; allotype, female, 

 in that of the California Academy of Sciences. 



Type locality. Mono Lake, Mono County, California ; collected by 

 Mr. Chas. L. Fox, on June 17, 1917. Seven specimens studied. 



Angulatus differs from the other species in its dark antennae, distinct 

 basal angles of the pronotum, stouter ovate form and simple modification 

 of the disk of the fifth ventral in the male. It resembles montanus Casey 

 in appearance. 



Listrus salicis, new species. Form oblong-oval, similar in the sexes 

 and moderately convex. Color black, dull in lustre with a feeble aeneous 

 tinge; mouth-parts piceous; second joint of the antennae rufous, third, 

 fourth and fifth joints more or less rufo-piceous, apical joints black; 

 tibiae and tarsi piceous, the latter may be rufo-piceous. 



Pubescence rather coarse, linearly subsquamiform, rather short and 

 recumbent, quite dense, plumbeo-cinereous on the upper surface; longer 

 on the under parts, dense and snowy-white on the prosternum and 

 sternal side-pieces, slightly darker on the abdomen. The dark brownish 

 hairs form rather moderate-sized maculae which are usually rather obso- 

 lete toward base but otherwise arranged as follows : An occasional small 

 humeral and parascutellar macula; post-basal small at middle of each 

 elytron, or obsolete ; submedian fascia obsolete or very narrow and zig- 

 zag, or broken into two short oblique dots on elytron ; subapical trans- 

 verse row of four maculae which are usually subequal and discrete; 

 apical maculae small or obsolete. Pronotal maculae obscure, discernible 

 as faint clouds, the central one at times appears somewhat oblong. 



Head about as long as wide, eyes large and moderately strongly 

 convex ; front broadly and rather deeply impressed between the antennae 

 and anterior canthi of the eyes, feebly convex toward vertex; surface 

 rather finely and densely indentato-punctate, punctures coarser 'on the 

 vertex with intervals rugulose; muzzle short and relatively small; hairs 

 at sides of the front and before the eyes rather dense and white. 

 Antennae similar in the sexes, moderately long and attaining the 

 pronotal base, rather slender and moderately compressed, apical three 

 joints slightly thickened; second joint oval, slightly longer than wide; 

 third feebly obconical nearly cylindrical, subequal in length to the 

 fourth, the latter obconico-triangular, apical margin slightly oblique, 



