108 BULLETIN 63, UNITED STATES NATIONAL MUSEUM. 



Dickinson County (August) and eastern Woodbury County (Sep- 

 tember) ; it extends as far east as Independence, Buchanan County, 

 September, on a broad, dry sand flat, along theWapsipinicon Bot- 

 tom " (H. F. Wickham, Iowa Acad, of Sci., 1899) : Wyoming 

 (Cheyenne, May; collectors, Hubbard and Schwarz) ; Montana 

 (Helena, May; Assiniboine, August; collectors, Hubbard and 

 Schwarz) ; Southern Dakota (Sioux Falls, May, H. Soltau) ; British 

 America (Medicine Hat, September, C. V. Riley). 



Xumber of specimens studied, 110. 



Type destroj^ed. 



Type-locality given by Say^ Missouri and Arkansas. 



Salient type-characters. — Body oblong-oval, with numerous minute 

 prostrate hairs. Thorax transversely subquadrate, anterior edge 

 concave ; basal edge rectilinear, covering the base of the elytra ; lateral 

 edge arcuate; anterior angles rounded; posterior angles excurved. 

 Elj^tra scabrous, with three elevated lines, a common sutural, and a 

 lateral one on the edge, intermediate spaces broad, flat, not concave, 

 and sometimes with the appearance of a slightly elevated longitudinal 

 line alternating with the others (Say). 



Diagnostic characters. — A distinct species, (hill in color, sparsely 

 pubescent, and with more or less costate elytra. 



In the typical form there is a humeral, a subhumeral, sutural, and 

 two discal costie, the intervening costaj obsolete or very feebly indi- 

 cated, with the intervening spaces flat and wide. 



In the costate form all of the costa^ are developed and of about 

 equal prominence; the individuals are usually under the average 

 size and decidedly oblong in form; males more frequently observed. 



The individuals of the oval form are more or less oval and rather 

 convex, the costse are normal, strong, and frequently glabrous, the 

 pubescence may be blackish or of the normal fulvous color. 



The robust form is a larger, stouter, and decidedly more coarsely 

 sculptured variety. Laterally and at apex the murications are quite 

 spiculiform. 



The mentum is comparatively small, triangular to trapezoido- 

 triangular in general outline; surface feebly convex, more or less 

 slightly impressed along the sides at times, rather finely punctate, 

 each puncture with a short seta. 



Prosternum comj^aratively broad between the coxee, usually convex 

 antero-posteriorly and more or less arcuate or vertical behind, rarely 

 subtruncate or submucronate. 



The mesosternum is usuallj^ arcuately vertical and moi-e or less 

 moderately concave, sometimes feebly so. 



The intercoxal process of the first abdominal segment is quadrate 

 and equal in length to the post-coxa 1 part of the same segment ; it is 

 also equal to the second in length; the third segment is one-half 



