H. C. FALL. 55 



cuius is " closely allied to robustuhis with which it agrees in 

 form and vestiture." In LeConte's description of robustulus 

 the thighs are said to be not toothed, and the second and 

 third funicular joints equal or nearly so. Casey describes 

 moleculus as having the front thighs toothed and the second 

 funicular joint longer than the third. The front thighs are 

 really toothed in robustulus — LeConte was in error here — 

 while the second funicular joint is, or is not, appreciably 

 longer than the third according to the individual specimen 

 one is examining. As Casey described from an unique he 

 could not know this, but it is equally true in a series of both 

 eastern and western specimens, and here as well as in many 

 other species the variation is in some degree sexual. 



The characters given by Dietz for separating moleculus 

 from robustulus are in part individual and in part non-existant ; 

 e. g. he says that the second and third funicular joints are 

 together longer than the next three in robustulus, which is 

 not true. 



A. spliaeralciae n. sp.— Elongate oblong, piceous, beak, an- 

 tenae'knd legs bright rufous, vestiture exceedingly dense both above 

 and below, consisting of pale ochreo-cinereous scales which are on the 

 average about twice as long as wide, almost perfectly uniform in color 

 above except along the median line and at the sides of the prothorax, 

 where they are whitish. The scutellum is densely white, and there 

 are barely perceptible traces of short paler vittae on the sutural, fourth, 

 and sixth elytral intervals, Body beneath very densely clothed through- 

 out with whitish scales, wider at the sides of the sterna, and narrower 

 but not hair-like on the ventral segments. Antennal funicle 7-jointed, 

 second joint nearly twice as long as wide and not much shorter than 

 the two following joints united. Eyes and beak nearly as in appositus. 

 Prothorax very nearly as long as wide, subconical, apical constriction 

 feeble. Front femora with a small acute tooth, middle and hind 

 femora apparently unarmed. Hind tibiae (c?) straight, with a rather 

 feeble parallel sided dilatation in apical fourth. Length, 3 mm. ; width, 

 1.3 mm. 



The type is a c5^ from Phoenix, Arizona, taken on Sphaeral- 

 cea variabilis by Prof. Cockerell. With the type I associate 

 single specimens from Santa Rita Mountains, Arizona ; 

 Pike's Peak and Boulder, Colorado ; Wallace, Kansas ; and 

 Dakota. 



TRANS. AM. ENT. SOC, XXXIX. 



