50 Journal New York Entomological Society. ['^'°'- ^^i- 



Harr., which is without wings and a very awkward beetle out of the 

 water. Several of the species lack the agile swimming powers of 

 most Dytiscidcc. Hydroponis difformis Lee, Mains bicarinatus Say, 

 Agabiis semipunctatiis Kby. and even the big Scutoptcrus, are very de- 

 liberate in their movements and may be said to crawl rather than 

 anything else. 



Many of these forest species seem able to live where there is 

 little actual water, provided there is some moisture. Wickham in his 

 list of Bayfield, Wis., beetles says " a large part of the species of water 

 beetles were taken not in water, but under moss in damp spots, a pe- 

 culiarity which I have noted in some species of Agabus collected on 

 a previous trip to Alaska." Adams refers to this in his book on 

 Isle Royale. Shelford one year found Mains bicarinaius Say quite 

 common under old logs in damp places at Pine, Ind., and Mr. Loding 

 in Alabama says of this beetle " always under sphagnum moss in a 

 moist partly dried up swamp." 



The water-beetles of the forest are for the most part black or dark 

 in color, especially those species living in the deepest and darkest 

 woods. The very black rich earth of their habitat, and the compar- 

 ative lack of sunlight, undoubtedly affect the coloration of the beetles, 

 as is commonly believed. The species living in open meadow ponds 

 are much oftener pale in color or markings, e. g., Hydrocanthus, Lac- 

 cophilus, Coelambus, Copioiomus, Rhanius binoiaius Harr. and calidus 

 Fabr., Colymbctes scnlpiilis Harr., etc. 



HI. Bodies of Running Water. 



While the Parnidas live almost exclusively in running water, the 

 number of species of Dytiscidse so found is small by comparison with 

 the number living in ponds. But these species are very interesting 

 and indeed seem to possess a certain nobility of appearance, nearly all 

 of them being very bright, shining and clean looking. As Dr. Regim- 

 bart advised his correspondents, " they live usually along the edges 

 of shallow streams, nearly always in small brooks in whose beds are 

 stones, and along whose edges there are masses of the half floating 

 roots of aquatic plants." 



The genus Hydroponis furnishes most of the species of Dytiscidse 

 found in running water. Of this genus pulcher Lee, melliiiis Lee, 

 and striaio-punctatus Melsh. live in the shallow places of the smaller 



