OBNU8 TKNTHREDO. 71 



The males, as a rule, do not differ much in colora- 

 tion from the females. With some species, however, 

 it is considerably lighter (T. zonata) ; parts whicli are 

 quite black in the female being yellowish or red in the 

 male. Some males have the legs lined with black (T. 

 fit, &c.), others have the abdomen black, while it is 

 banded with red in the other sex. 



The geographical distribution of this genus is very 

 wide. The species are very numerous in the Palae- 

 arctic, Oriental, and Nearctic regions, occurring in all 

 their subregions. They are absent from the Neo- 

 tropical, Australian, and Ethiopian regions. 



The green species are temperate or northern forms, 

 yellowish temperate or tropical, while the blue or green 

 metallic species inhabits warm or tropical regions. 



There are some sixty European species, and sixty- 

 seven (including, probably, some pertaining to Tenihre- 

 dopsis) are recorded from the United States and Canada 

 by Cresson in his " Catalogue of the Tenthredinida3 and 

 Urocerida3 of North America." (Trans. Am. Ent. 

 Soc., viii, 1880.) 



Obs. It must be confessed that the differences 

 between Tenthredo, as here defined, and the next genus, 

 are not very great. The most certain distinctions 

 consist in the deeply emarginated clypeus, the short, 

 thick antennas, having the third joint always consider- 

 ably longer than the fourth, the mesonotum usually 

 punctured, and the hinder wings having always two 

 distinct middle cellules. 



In Tenthredopsis, as here restricted, the species have 

 the antennas long, thin, filiform, with the third joint 

 about the same length as the fourth ; the cheeks are 

 well developed, the eyes do not reach to the base of the 

 mandibles ; clypeus truncated, or if incised, only to a 

 very slight extent, while we have the difference, 

 although not a constant one, in the posterior wing of 

 the c?. "We have, furthermore, a uniformity in the 

 body form and coloration. The entire body is smooth, 



