262 



FAMILY VI. — HYDKOPHILID^E. 



KEY TO INDIANA SPECIES OF CYMBIODYTA. 



a. Form oval ; elytra with rows of coarser punctures distinct at least on 

 sides. 



b. Color wholly piceous. fimbbiata. 

 1)1). Dull brownish-yellow ; head black, with a large yellow spot in front 

 of each eye. 509. blanchabdi. 



aa. Form oblong; elytra without rows of coarser punctures; piceous with 

 a pale border. lacustbis. 



O. fimbriate/, Melsh., 4.5-5.5 mm. in length, occurs from Canada 

 to Pennsylvania and Texas. G. lacustris Lee, 4-4.5 mm. in length, 

 is a boreal species which may occur in northern Indiana. 



509 (9319). Cymbiodyta blanchabdi Horn, Trans. Amer. Ent. Soc, XVII, 



1890, 25S. 



Rather broadly oval, scarcely narrowed in front, moderately convex. 

 Dark smoky brown ; margins of thorax and elytra paler ; head black with a 

 reddish-yellow spot in front of each eye; beneath piceous or brown, tarsi 

 paler. Thorax and elytra rather closely punctate, the rows of coarser 

 punctures represented only by a few distant punctures, except the outermost 

 row, which is distinct. Sutural stria well impressed and reaching two-thirds 

 to base. Length 4 mm. 



Steuben, Putnam and Lawrence counties; scarce. March 25- 

 August 11. Taken on the under side of fiat stones in swift running 

 water. Resembles Philhydrus ochraceus, but more broadly oval in 

 form. 



XIV. Helocombus Horn. 1890. (Gr., "marsh + border. ") 



Maxillary palpi very long and slender, the last joint distinctly 

 shorter than third ; thorax without a basal marginal line ; elytra dis- 

 tincly striate. One species is known from the eastern United States. 



510 (1629). Helocombus bifidits Lee, Proc. Phil. Acad. Nat. Sci., VII, 



1855, 371. 



Oblong-oval, subdepressed. Piceous, shining; tarsi and narrow margin 

 of thorax and elytra paler. Thorax closely and finely punctate. Elytra 

 rather deeply striate, the striae entire except the inner three ; intervals on 

 sides convex, flatter on disk, rather coarsely punctate, Length 5.5-7 mm. 



Lakes of northern half of State, frequent ; also in Marion and 

 Fountain counties. April 3-August 20. 



XV. Hydrobius Leach. 1817. (Gr., "water + life.") 



To this genus, as now limited, belong six of the larger species of 

 the Henshaw list. They have the last joint of the maxillary palpi 

 always longer than the third, and the elytra with either ten rows of 

 punctures or 10-striate. Three of the species have been taken in 

 the State, while another may occur. 



