34 DESCRIPTIONS OF NEW SPECIES. 



dorsalem puncto postico impressis ; abdomine parce punctato, apice pal- 

 lidiore, antennaruni basi pedibusque piceo-testaceis. Long. '11 — -13. 



Middle and Southern States. This small species has the punc- 

 tures of the thorax very well marked ; the antenna? are rather 

 stouter than usual, and not pale at the tip. In one specimen 

 there are two impressed punctures behind the middle of the ely- 

 tra inside of the dorsal series ; there is likewise a supplementary 

 dorsal puncture on the thorax behind the one near the middle on 

 the right side. 



114. M. consors. Nigro-piceus nitidus, thorace punctis utrinqne 

 quatuor dorsalibus ; elytris serie dorsali duplici, alteraque externa dis- 

 tincta ; abdomine piceo, parce punctato, segmentis margine postico 

 piceo-rufo, antennis fuscis basi pedibusque fusco-testaceis. Long. -14. 



Michigan. Rather broader than the preceding, and readily 

 distinguished by the dorsal punctures of the elytra being arranged 

 in two rows, each containing six or seven well-marked punctures ; 

 half way between the dorsal series and the margin is another row 

 of four or five smaller punctures. The punctures of the thorax 

 are well marked. 



AC1LOPHORUS Nokdmann. 



115. A. gilensis. Niger nitidus, thorace antrorsum modice angustato, 

 lateribus rotundatis, elytris fortiter haud dense punctatis, abdomine 

 subtiliter punctato, longius nigro-piloso ; pedibus anterioribus piceis. 

 Long. -24. 



Gila River, below Pima villages. Of the same size as A. pro- 

 nus, but with the elytra more coarsely and less densely punctured ; 

 the pubescence of the abdomen is longer, and the thorax is less 

 narrowed in front and more rounded on the sides. 



Sexual differences were not observed by Erichson or by Kraatz. 

 I find in our species that the claws of the anterior tarsi of the 

 male are much larger than those of the female. The species all 

 occur on the margin of streams. 



116. A. pratensis. Niger nitidus, thorace antrorsum modice angus- 

 tato, lateribus parum rotundatis, elytris subtilius punctatis, pubesceuti- 

 bus, abdomine subtiliter pun?tato, longius pubescente, tarsis piceo-tes- 

 taceis. Long. *28. 



Kansas. Much larger than A. pronus, with similar sculpture, 



