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North American Coleopterous Insects. 



171 



feet 



.with a few scattered, slightly impressed punctures: scutel 

 rather large : elytra with four striae of impressed punctures 

 and an approximate marginal one : 

 base of the thighs, piceous. 



Length nearly three fifths of an Inch* 



A specimen was sent to me by Mr. J. Barabino. The 

 whole surface is covered with very minute crowded punc- 

 turesj not at all visible without a pretty good lens. 



Hydrophilus, Fabr. 



1. H. mergus. Black, highly polished ; sternum not 

 reaching the middle of the venter. 



Inhabits Mexico. 



Sody highly polished, black, oblong-oval : head with 

 an abbreviated line of impressed, confluent punctures on 

 the inner orbit ; a much arcuated line of punctures from 

 the anterior canthus terminates between the eyes : thorax 

 ' with a much abbreviated, oblique line of punctures each 

 side : elytra with three series of distant, obsolete punc- 

 tures ; exterior series remote from the others : sternum 

 not canaliculate, not extending to the middle of the ven- 

 ter: feet more or less piceous. 



Length nearly seven twentieths of an inch. 



In comparison with H. natatory Nob. which it closely 

 resembles, the surface is more highly polished, the 

 sternum much shorter and without any appearance of a 



^ 



groove between the anterior pairs of feet. 



2. 1^. exstridtus. Subsutural stria none, black; thoracic 

 edge and beneath piceous. 



Inhabits Louisiana. 



Body short-oval or rounded, convex, glabrous, black ; 



