THE HISTER BEETLES. 



003 



cc. Front tibiae with a small tooth on the inner side near the base; spine 

 of presternum convex. Subgenus IV. Cylistiux. 



Subgenus I. (Histek.) 



Rounded or oval, convex species, having the elytra always 

 striate; thorax nearly always with two marginal striae, the outer 

 often short ; hind tibia? narrower at base than at apex, and with two 

 rows of spines. Since the number of species and varieties of the 

 subgenus taken in the State is 22, while five others may occur, they 

 are for convenience arranged in four groups, separated as follows: 



KEY TO GROUPS OF INDIANA SPECIES OF THE SUBGENUS HISTEB. 



a. Margin of thorax fringed with short, hairs; antenna] cavities shallow. 



Group A. 



aa. Margin of thorax not fringed; antenna 1 cavities deep. 

 1). Prosternum convex without strise on the sides. 



c. Mesosternum emarginate in front. Group B. 



cc. Mesosternum truncate in front. Group C. 



1)1). Prosternum more or less flattened with a stria on each side ; meso- 

 sternum very feebly emarginate; outer thoracic stria usually en- 

 tire. Grou P D - 



Group A. 



To this group belong two rather robust species having the en- 

 tire margin of the thorax fringed with short yellowish hairs. One 

 of the two has been taken in the State, while the other probably 

 occurs. 



KEY TO SPECIES OF GROUP A. 



a. Front tibia* bidentate ; outer marginal stria of thorax entire; color 

 black and red. 1143. biplagiatus. 



aa. Front tibiae not dentate; outer marginal stria abbreviated; color wholly 

 black. L^VIPES. 



1143 (3472). Hister biplagiatus Lee, Bost. Journ. Nat. Hist.. V, 1S45. 

 55, pi. 3, fig. 4. 



Broadly oval. Black; elytra each with a large curved red space on 

 the center. Thorax with two entire strife, its surface smooth or nearly so. 

 Elytra without trace of subhumeral stria; each with three entire dorsal 

 striee and a trace of fourth at base and apex, the sutural extending from 

 apex one-third to one-half towards base. Pygidium sparsely and rather 

 finely punctured. Length 5 mm. 



Cass County; rare. One specimen dug from a burrow in a 

 sand bank by Dr. Robert Hessler. April 17. Probably occurs 

 sparingly throughout the southern two-thirds of the State. 



H. Icevipes Germ., length 3.5—1.5 mm., is said to occur from 

 Pennsvlvania to Georgia. 



