THE WATEE SOAVENGBH BEETLES. 259 



■500 *(1614). Berostjs stkiatus Say, Journ. Pbil. Acad. Nat. Sci., V, 1825, 

 188. 

 Elongate-oval, convex. Head as in peregrinus but without impression 

 betvs^een the eyes; thorax and elytra dull greenish-yellow, the former with 

 a double fuscous line on disk ; each elytron with eight or ten small, remote, 

 indistinct blackish spots. Elytral stria; distinctly impressed, finely punc- 

 tate; intervals flat, with rather coarse punctures. Length 4-5 mm. 



Throughout the State ; common. Peljruary 26-October 21. Hi- 

 bernates as imago, specimens having been taken in February from 

 beneath log buried deeply in sand, while others were dredged from 

 a pond in early March. 



B. pugnax Lee, 5-6 mm. in length, and colored much as in 

 pantherimis, is known from Illinois and Missouri. B. exiguus Say, 

 2.5 in length, occurs from Pennsylvania to Louisiana. 



IX. CH.i;TAETi-miA Stephens. 18-32. (Gr., "bristle -t- joint.") 



Very small species having the first joint of antenna^ long and the 

 body contractile. They occur about the margins of ponds and lakes. 



501 (1G19). Ch^tabthkia paluda Lee, Proc. Phil. Acad. Nat. Sci., 1861, 



342. 

 Hemispherical, very convex, shining. Above dull brownish-yellow ; head 

 black, shining ; disk of thorax often with a fuscous blotch ; beneath black. 

 Elytra very sparsely and finely punctate; sutural striiB distinct. Length 

 2 mm. 



Lakes of Laporte, Marshall, Fulton, and Starke counties; fre- 

 quent. June 16-August 31. A member of the boreal fauna. This 

 is the form described as nigriceps Lee. 



X. Laccobius Er. 1832. (Gr., "pool or lake -h life.") 



502 (1621). Laccobius agilis Rand., Best. Journ. Nat. Hist., II, 1838, 19. 

 Subrotund, convex. Head and disk of thorax blackish-iridescent, the 



margins of latter broadly pale yellow ; elytra pale, the strite dusky ; under 

 surface black, legs pale. Head alutaceous, finely and sparsely punctate, 

 the margin in front of eyes yellow. Thorax three times as wide as long, 

 as wide at base as elytra, finely and sparsely punctate. Punctures of ely- 

 tra very small and close-set in regular rows. Length 2-3 mm. 



Throughout the State ; common, ilay 26-September 3 



XI. Philhydeus Sol. 1S34. (Gr., "love -^ water.") 



Small oblong-oval beetles, piceous or dull brownish-yellow in 

 hue and having the upper surface regularly and rather finely and 

 closely punctured ; elytra with four rows of coarser punctures, these 



