THE CANADIAN ENTOMOLOGIST. 243 



A. Smaller pale greenish forms ; western pallidus, Baker. 



A A. Larger, darker, brownish to blackish forms. 



B. Scutel yellowish, whole insect pale brown ; 



Nevada inter?nedia, Baker. 



BB. Scutel brown to black, body of various shades of brown, 

 but mostly dark. 



C. Length, 6-7 mm.; E. U.S. to ^tw^ddi . ?wvcEboracefists, Fh. 



CC. Length, 7-9 mm.; Colo, to Nevsid3i. .occide/ifa/is, Baker. 



BBB. Scutel and most of the body above, with the legs, 



black J>/ufon/us, Baker. 



Genus Liorhyssus, Stal. 

 This genus has but one known American species, hyaliniis^ with 

 numerous forms everywhere. In but few cases are these even geograph- 

 ical, since the same ones constantly recur in widely-separated localities and 

 in all sorts of combinations. On^y in the extreme south have I found any 

 clearly-marked varieties. In Cuba all the individuals taken by me are 

 very dark, with disc of pronotum almost black. Some of these southern 

 forms deserve distinguishing names, if South American extensions of the 

 species have not already been named. Uhler has described one of the 

 western forms as viridicatiis. 



Genus Niesthrea, Stal. 



This genus contains the most highly-coloured species of the group, 

 and is the largest genus in North America. Frequently small forms had 

 been determined for me as ventralis and sidce, but both of these, together 

 with scutatus and validiis^ were originally described as about 10 mm. in 

 length. The large forms constitute a well-defined series, which, with a 

 large amount of material before me, I believe to be of but specific value. 

 The validus of Uhler varies completely into the scutatus of Stal, which is 

 one of the most common species of the Pacific Slope. Venira/is is but 

 sidce with lateral rows of black dots on each ventral segment. Large series 

 collected in Nevada, Middle and Southern California and Mexico illustrate 

 very clearly the relation between these large forms. The small forms of 

 the genus known to me appear to belong to but three specific groups, 

 but with many forms each ; these are the lateralis of Say, \.\\q pictipes of 

 Stal, and the sidcE of Fabricius. Nigristernum, recognized by Fitch and 

 described by Signoret, I believe to be the merest colour-form oi lateralis. 



