414 AMERICAN PACHYBRACHYS (cOLEOPTERA) 



extreme the yellow is strongly predominant, the darker mottling 

 being mainly due to the very numerous and irregularly disposed 

 dark punctures, which on the prothorax are then usually aggre- 

 gated so as to show vague traces of standard spots. In general 

 the females are darker than the males. The front legs are often 

 in great part yellow, the thighs with a long black spot above; 

 the middle and hind thighs may be described as yellow broadly 

 banded with black, or black with base and tip yellow. The front 

 and middle tibiae are usually in part yellow, the hind tibiae are 

 typically dark throughout, but are slightly yellow at base in some 

 examples. Occasionally in very dark examples the legs are almost 

 entirely black; there appears always, however, to be a small yellow 

 spot at tip of middle and hind thighs, and usually on the front 

 face of the anterior thighs. In the large series before me, which 

 I have assigned to this species, I note a little variation in the width 

 of the front between the eyes, these being slightly but distinctly 

 less distant in a series from Mobile, Ala., this, however, is not 

 correlated with any other characters that I can discover. The 

 front claws of the male are not appreciably enlarged, that is to 

 say — they are on careful comparison only very slightly larger 

 than those of the middle and hind feet. Some trifling variation 

 in the size of the front claws is discernible in the series at hand 

 but it does not appear to me to be significant. 



Great uncertainty has prevailed up to this time as to the iden- 

 tity of the true atomarius of Melsheimer, and about all the small 

 mottled species of the Atlantic Coast region appear under this 

 name in the various collections which I have examined. Halde- 

 man, who wrote but a few years after Melsheimer, assumed the 

 species to be the same as femoratus Oliv. and so placed it, with a 

 query; he then proceeds to describe the real atomarius as his own 

 infaustus. Suffrian probably had authentic specimens of both 

 atomarius and infaustus, for while he gives descriptions of both, 

 he expresses doubts as to the distinctess of the latter. LeConte, 

 strangely enough, was entirely off in his interpretation, using 

 the name atomarius for the peccans of Suffrian. Recently, Bow- 

 ditch has followed LeConte, and redescribcs some of the paler 

 western specimens of atomarius as his atomus. 



A critical study of material from the Melsheimer collection, 

 now contained in the Museum of Comparative Zoology at Cam- 

 bridge, enables me to fix with almost absolute certainty the 



