276 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



coming paler and leaving the apices a dull testaceous; shining; mod- 

 erately clothed with whitish pubescence, which is longest on head 

 and prothorax. Head with front moderately coarsely, not very 

 densely, somewhat rugosely punctate, occiput finely punctate and 

 very finely rugulose ; eyes moderately prominent ; antennae half as 

 long as body, rather stout; joints two and three short, obconical, 

 equal in length, joint three more slender than joint two, together just 

 visibly longer than joint four; joints four to ten elongate, subequal, 

 feebly serrate, joint eleven one-third longer than tenth. Thorax one- 

 half longer than wide at apex, base narrower than apex, subapical 

 constriction feeble, at basal fourth strongly compressed; ante- 

 scutellar impression feeble, an obtuse tubercle each side of impression; 

 surface finely rugulose, distinctly so at middle of disk. Elytra twice 

 as wide at base as thorax at base; humeri distinct; sides straight, 

 feebly divergent to apical fourth, thence arcuate to apex; apices con- 

 jointly rounded; disk feebly convex, with rows of coarse punctures 

 in basal half, the punctures abruptly much reduced in size and depth 

 behind the middle and becoming obliterated at apex; intervals 

 nearly flat, near suture subequal in width to punctures, narrower 

 toward the flanks, finely, irregularly punctulate, a fine hair arising 

 from each puncture. Metasternum rather finely, feebly, sparsely 

 punctate, the punctures separated by four or five times their own 

 diameter, a little closer at the middle. Abdomen minutely, very 

 densely punctulate. Length, 5.9-6.2 mm. 



Male. — Fifth ventral segment broadly feebly arcuately emarginate; 

 sixth ventral short, broadly rounded, arcuately emarginate at apex; 

 last dorsal much larger than last ventral, sides narrowing to apex, 

 which is broadly sinuate-truncate. (Plate 43, figs. 16, 17.) 



Female. — Fifth ventral truncate at apex, a small distinct fovea at 

 middle of apical margin extends onto basal portion of sixth ventral, 

 the latter short, truncate at apex; last dorsal semicircular, larger 

 than last ventral. (Plate 43, figs. 18, 19.) 



Type locality. — Springdale, Utah. 



Type. — In author's collection, No. 1145; paratype in Mr. Warren 

 Knaus' collection. 



Described from two specimens sent me by Mr. Warren Knaus. 

 The type, a male, Springdale, Utah, June 16, 1919 (Tom Spaulding) ; 

 paratype, a female, St. George, Utah, 2,800 feet, May 22-June 12, 

 1919 (W. Knaus). 



Closely allied by antennal structure to isabellae Wolcott, of which 

 species at first sight it was thought to be a variety; however, further 

 study revealed too many points of structural difference to permit of 

 this conclusion. The robust form, the presence of an ante-scutellar 

 impression, the proportionately longer thorax, the coarser elytral 

 punctuation, with the abrupt reduction in size of the punctures be- 



