250 FAMILY VI. IIYDROPIIILID.'E. 



I. HELOPHORUS Fab. 1776. (Gr.. "tubercle -i bearing. ") 



Thorax rough, with granulate depressions, and marked with five 

 longitudinal sulci, of which the intermediate, or those on either side 

 of the middle one, are often very sinuous. Five species have been 

 taken in Indiana, while one other may occur. 



KEY TO INDIANA SPECIES OF HELOPHORUS. 



a. Elytra without tubercles <ir alternate elevated lines. 



1>. Larger. 5-7 nun.; head and thorax shining, sparsely punctate; inter- 

 mediate sulcus but slightly undulate. OBLONGUS 



l>h. Smaller, not over 4.5 mm. 



c. Thorax with hind angles obtuse, not narrowed at base; color pic- 



eous-brown. 



'/. Thorax with sides feebly rounded in front, nearly straight be- 



hind; intermediate sulci strongly sinuate. 47S. LACUSTRIS. 



(//. Thorax with sides regularly rounded; intermediate sulci nearly 



straight. 47!).. NITIDCLUS. 



<<: Thorax with hind angles rectangular. 



c. Thorax slightly narrowed at base, its sides subsinuate; color 

 light brownish-yellow with indistinct fuscous markings. 



4so. I.IXEATUS. 

 <'<. Thorax not narrowed at base, sides nearly straight. 



481. LINEARIS. 



<KI. Elytra with tubercles on the third, iit'th and seventh intervals. 



482. TU15ERCULATUS. 



//. olloiii/an Lec. was, like lacustris and iiititlidus, described 

 from Lake Superior, and like them may occur in northern Indiana. 



47s ( 1543). IlELopnoRVs LACCSTRIS Lec.. Agass. Lake Sup., 1850, 217. 



Oblong, subdepressed. Piceous-brown, slightly bronzed; head and thorax 

 tinged with greenish; legs reddish-brown. Thorax two-thirds wider than 

 long, covered with rounded flattened granules; sulci narrow, deep, the in- 

 termediate ones strongly sinuate. Punctured strhe of elytra deep. Length 

 4-4.5 nun. 



Lake and Laporte counties; scarce. May 12- August 26. 



47!) (1545). HELOPHORUS KITIDULUS Lec., Proc. Phil. Acad. Nat. Sci., VII, 



1855, 357. 



Elongate, subdepressed. Piceous-brown, shining, distinctly bronzed; legs 

 pale, the femora darker. Thorax one-half wider than long, the sulci broader 

 and more shallow than in /</c//.\/r/\. the intermediate ones but slightly sinu- 

 ous. Intervals of elytra more narrow, the stri;e deep. Length 3-3.5 mm. 



Lake County, near Oshorn and Pine; rare. April 21-May 2o. 



