Sept., I9I7-] Fall: New Dytiscid^. 181 



truncate, their tips not in the least sinuate, and consequently not at all promi-, 

 nent on the median line. Metasternum finely, sparsely punctate at middle, 

 more coarsely and closely at sides ; postcoxal plates and first two ventral seg- 

 ments rather sparsely, moderately coarsely punctate, following ventrals more 

 finely and sparsely so. Length 3.35 to 4 mm.; width 1.7 to 1.85 mm. 



Of this species there are before me five examples (inchicling the 

 type) from Starr Lake, 4,890 ft., White Mts., N. H. (Sherman) ; one 

 example from Randolph, N. H. (Sherman) ; one from Farmington, 

 N. H., collected by the writer, and one from Tyngsboro, Mass. 

 (Blanchard). 



There are no obvious sexual differences in the eight specimens at 

 hand. In all, the front tarsi are moderately broad with the joints 

 slightly decreasing in width from the base, the middle evidently nar- 

 rower with the joints more conspicuously diminishing in width. The 

 third joint of the middle tarsus is moderately emarginate supero- 

 distally for the reception of the terminal joint but does not seem to 

 be truly bilobed, the terminal joint projecting beyond the third a 

 greater distance than the length of the latter. The claws of the front 

 tarsi are mutually equal, not appreciabl}^ stouter, but distinctly shorter 

 than those of the middle tarsi. 



Concerning this species, specimens of which were sent to him by 

 the writer in 1902, Dr. Sharp wrote: "Unknown to me; seems not 

 very near anything." It is really quite similar in general aspect to 

 two or three species of the americanus type, but is slightly smaller 

 than these, and at once separable by the shorter antenna] joints. 



Hydroporus dentellus new species. 



Moderately elongate oval, moderately shining in both sexes, evidently 

 pubescent ; dark brownish piceous, the prothorax and sides of the body ante- 

 riorly becoming gradually rufopiceous, the head rufous ; in some examples, 

 perhaps less mature, the upper surface is brownish testaceous. Body beneath 

 dark rufopiceous, the sides and apex of abdomen gradually somewhat paler ; 

 prothorax rufous, legs dark rufous. Head finely punctate, feebly impressed, 

 clypeus not thickened. Antennae moderate, rufotestaceous at base, the outer 

 joints more or less completely infuscate. Prothorax finely margined at sides, 

 disk sparsely, finely punctate, more coarsely and closely so toward all the 

 margins. Elytra evenly, not very finely punctate, the punctures separated by 

 from one to one and one half times their own diameters as a rule, being, as 

 is often the case, a little closer transversely than longitudinally. Body be- 

 neath more coarsely but rather sparsely punctate, the abdominal punctures 

 finer and sparser at the middle and toward the sides posteriorly, as usual. 



