200 AMERICAN COLEOPTERA 



Siskiyon County (Ricksecker) and Lake Tahoe (Fall), California, 

 Oregon, Olympia, Wash, and Vancouver Island. 



Group III. flavicauda. 



Head not inserted in the thorax to the eyes; mentutn without 

 forameniform punctures; antennae submoniliform, the first three 

 joints normal, the second and third subequal, joints 4-10 shorter 

 and more rounded, subequal, the terminal longer, subacute at tip. 

 Thorax broadly margined, the margin translucent, Elytra rounded 

 at tip, with two small dorsal punctures on the third interval very 

 close to the third stria ; recurved portion of the sutural stria nearly 

 parallel to the margin, not hooked at tip; marginal stria much less 

 deep or nearly effaced at middle. 



The first two joints of the anterior tarsi are dilated in the males. 



But one species is included in this group. 



4. T. flavivaiitla Say (Plate VI, lig. 3).— Form rather broad, feebly eon- 

 vex. Color dark pieeous or nearly black, the apical third of the elytra yellowish. 

 Surface finely and rather sparsely alutaceus, slightly shining. Head as wide as 

 the thorax at apes ; frontal grooves short, not extending behind the middle of 

 the eyes; eyes moderately large and prominent; antennae less than one-half as 

 long as the body, nifo-testaceous, slightly darker towards the tip; palpi pale tes- 

 taceous, the terminal joints of both pairs rather longer than usual in the genus. 

 Prothorax about one-half wider than long, slightly wider at base than apex, sub- 

 quadrate; apex emarginate, the anterior angles slightly prominent : transverse 

 impressions distinct, the posterior deeper; median line moderately deep, extend- 

 ing between the transverse impressions ; basal impressions moderate; base trun- 

 cate ; sides feebly arcuate from apex nearly to base, obsoletely sinuate in front 

 of the hind angles, which are rectangular and not carinate. Elytra oblong- 

 ovate, nearly one-half wider than the thorax, the five inner striae moderately 

 distinct; striae impunctate; dorsal punctures very small, the first slightly in 

 front of the middle, the second about one-fourth from apex ; intervals nearly flat, 

 each with an irregular row of minute punctures, from each of which proceeds a 

 very short seta. Body beneath pieeous, the abdomen usually more or less tinged 

 with rufous, especially towards the tip. Legs rufo-testaceous. Length .06-. 07 

 inch ; 1.5-1.75 mm. 



A very well-known and characteristic little species, incapable of 

 being confused with any other in our fauna. 



The antennse resemble most closely those of Icevus and rufotesta- 

 ceus, except that the second joint is not longer than the third. 



The dorsal punctures of the elytra are very small (Plate VI, 

 fig. 3), so small, in fact, that they can usually be located only by 

 the setae arising from them, except under high power. The pres- 

 ence of irregular rows of minute setigerous punctures on the elytral 

 intervals recalls a similar arrangement in T. falli. 



