104 BESCRIPTION OF INSECTS 



gitudinal line each side on the base of the thorax and 

 elytra. 

 Length more than one-twentieth of an inch. 



Dytiscus lacustris. Melsh. Catal. 



Body rufous, obscure, with minute puncttn'es. 



Htadmih slightly impressed frontal spots; a/^^en/io?, terminal 

 joints tipped with blackish ; maxillary palpi blackish at 

 tip. 



Thorax blackish at base and tip, base each side with an im- 

 pressed, acute, oblique line not attaining the anterior 

 margin. 



Elytra with a blackish suture, base, and submargin, an im- 

 pressed, acute, longitudinal line as long as the thorax 

 arises from the middle of the base of each elytron, ap- 

 pearing to be a continuation of the lateral thoracic line. 



Pectus and feet pale rufous ; postpedus blackish ; venter 

 pale rufous. 



Var. a. Postpectus rufous. 



6. H. afflnis rufous, obscure ; a common impressed, longitu- 

 dinal line each side on the base of the thorax and elytra ; 

 elytra varied with longitudinal black lines. 



Length more than one-twentieth of an inch. 



Body rufous, obscure, punctured. 



Thorax blackish at base and in the middle, an impressed, 

 acute line each side at base not attaining the anterior 

 margin. 



Elytra with a blackish suture, base, irregular submargin and 

 intervening abbreviated lines, punctures of the disic rather 

 larger, distinct, impressed line of tlie middle of the base 

 of each elytron much abbreviated, obsolete. 

 Differs from the preceding, to which it is very similar, in 



[laving rather larger punctures on the disk of the elytra, 



more distinct lines, and in having the impressed ones of the 



base very short and indistinct. 



