646 BOSTON JOURNAL 



arcuated line each side before, and laterally [171] with a few 

 scattered, slightly impressed punctures : scutel rather large : ely- 

 tra "with four striae of impressed punctures and an approximate 

 marginal one : feet, excepting the base of the thighs, piceous. 



Length nearly three-fifths of an inch. 



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

 surfjice is covered with very minute crowded punctures, not at 

 all visible without a pretty good lens. 



[Does not differ from HijJrocliares ohtusatus, ante, 130. — 

 Lec] 



HYDROPHILUS Fabr. 



1. H. MERGUS. — Black, highly polished; sternum not reach- 

 ing the middle of the venter. 



Inhabits Mexico. 



Body highly polished, black, oblong-oval ; head with an ab- 

 breviated line of impressed, confluent punctures on the inner or- 

 bit ; a much arcuated line of punctures from the anterior can- 

 thus terminates between the eyes ; thorax with a much abbrevi- 

 ated, oblique line of punctures each side ; elytra with three se- 

 ries of distant, obsolete punctures ; exterior series remote from 

 the others ; sternum not canaliculate, not extending to the mid- 

 dle of the venter ; feet more or less piceous. 



Length nearly seven-twentieths of an inch. 



In comparison with H. natator nob., which it closely resem- 

 bles, the surface is more highly polished, the sternum much 

 shorter and without any appearance of a groove between the an. 

 terior pairs of feet. 



2. H. EXSTRiATrs. — Subsutural stria none, black ; thoracic 

 edge and beneath piceous. 



Inhabits Louisiana. 



Body short-oval or rounded, convex, glabrous, black ; [172] 

 with small, equal, equidistant, numerous punctures ; polished ; 

 palpi and base of the antennae pale yellow ; three last joints of 

 the latter fuscous ; thorax piceous on the lateral and posterior 

 margins; scutel small, with but few punctures; elytra destitute 

 of striae, and without any appearance of one on the sutural mar- 



[Vol. I. 



