March, 1913.] ShERMAN : HaBITS OF THE DyTISCID^. 49 



In the same woods at Peekskill, in isolated deep spring-like pools 

 full of dead leaves, Agabus gagates Aube is a common species and 

 practically the only one found in them. 



In more open spots in the woods at Tyngsboro, Mass., the ponds 

 contain Hydroporus tencbrosus Lee. and despectus Sharp, and Ilybio- 

 soma bifaria Kby. as well as several other species. 



In still more primitive forest growths than the Peekskill one — 

 in the sphagnum pools like those at the upper end of Hermit Lake 

 3,700 feet high on the east side of Mt. Washington, N. H. — and in 

 the very similar pools near the shores of the small lakes in the vicinity 

 of the Huron Mountain Club, on the south shore of Lake Superior, 

 we find 



Scutopterus angiistus Lee Both places. 



Scutopteriis Horni Crotch Lake Superior. 



Ilybius pleuriticiis Lee Both places. 



Ilybins discedens Sharp Both places. 



Agabus anthracinus Mann Hermit Lake. 



Agabus inscriptus Crotch Hermit Lake. 



Agabus semipuncfatus Kby Both places. 



Hydroporus tristis Payk Both places. 



Hydroporus n. sp. near despectus Sharp Hermit Lake. 



Dytiscus dauricus Gebl Hermit Lake. 



The common species of Sphagnum at Hermit Lake is Girgensohnii 

 Russ. of the ^. acutifolium group, as kindly determined by Dr. 

 Andrews through Mr. Davis. 



Of the forest pond Dytiscidae cited in these two tables, Hydroporus 

 tristis Payk. is quite often found in the more open ponds, while 

 Ilybius pleuriticus Lee. occurs in the Glen mill pond near Glen House, 

 N. H., about 1,600 feet elevation, and Agabus anthracinus Mann, was 

 very common one season in the Watson ice pond near the Ravine 

 House in the meadow at Randolph, N. H., 1,300 feet high. 



Two of our eastern species of Ilybius— confusus Aube and bigut- 

 talus Germ. — live in meadow ponds; pleuriticus Lee. lives both in 

 meadow and in forest ponds, while ignarus Lee. and discedens Sharp 

 seem to be forest inhabitants only. 



The other forest water beetles mentioned are very seldom seen 

 out of the woods. 



This fact is easy to explain in the case of Agabetes acuductus 



