The Pcntatomidae of Nebraska 17 



Nebraska as well as some additional material from southern 

 California, New Mexico, Colorado, Wyoming and South Dakota. 

 These specimens show an extremely wide range of variation. 

 Some are undoubtedly bioculahis while others might well be cir- 

 cumcincHis although there are numerous intermediates between 

 the two extremes. VanDuzee separates the two mentioned 

 forms, hiociilatus and circumcinctus, on the coloration of the 

 antennae and the form of the pronotum. The antennae in my 

 specimens show every grade of coloration from the condition in 

 which they are entirely black to that where the first two joints and 

 the basal half of the third joint are pale or rufous. There is also 

 some variation in the shape of the pronotum, but no decided or 

 abrupt difference. In short, I am inclined to believe that the two 

 so-considered species are but two extremes of an exceedingly 

 variable form ; at least I am unable to separate them. Possibly 

 future study may make their relations more certain. 



Two females, one from the bad-lands of Sioux county, Ne- 

 braska, the other from Las Vegas, New Mexico, agree very well 

 with the description given by VanDuzee of his variety "b" of 

 P. exaptus {Trans. Am. Ent. Soc, XXX, pp. 65-66) only my 

 specimens have the femoral spine distinctly developed, as much 

 so as do any of the specimens of the other varieties of hioculatiis. 

 They are but slightly smaller than the average of the species and 

 vary in other particulars of only minor value. Both the pale and 

 dark forms of typical biocnlatns occur in the state as do some 

 exact intermediates, though there are no intermediates between 

 either of these forms and the two females mentioned above. The 

 species is found commonly feeding on the larvae of the Colorado 

 potato beetle Leptinotarsa decemlineata. 



[Perilloides circumcinctus (Stal). 



1862. PeriUus circumcinctus Stal, Stett. Ent. Zeit., XXIII, p. 89 (note). 

 1872. Perilliis marginatus Provancher, Nat. can., IV, p. 74. 



I find nothing in the collection that I can satisfactorily separate 

 from biocidatus in the direction of this species. Uhler records 

 it, however, from this state in 1876 (Bull. U. S. Geo!. Geog. Surv. 

 Terr., No. 5, ser. 2, p. 16), as distinct from bioculatus and I 



235 



