8 GENUS CIMBEX. 



One species (0. sylvarum) is usually distinguished by 

 having a fuscous fascia in the first discoidal cellule, 

 and the edges of the wings are also fuscous, while 

 usually C. lutea is distinguished by its wings wanting 

 entirely these fuscous clouds ; but I have seen speci- 

 mens of sylvarum with the wings completely hyaline, 

 and of lutea with faint indications of the fuscous tint 

 along the edge and at the discoidal cellule. I thought 

 once (like Zaddach, loc. cit., p. 243) that the form of 

 the scutellum would give a good specific character, but 

 soon found that this also varied, especially with bred 

 specimens. Then the posterior coxas and femora vary 

 in length and thickness in the males. In some bred 

 specimens I have examined they are not much longer 

 or thicker than the middle pair, while with caught 

 specimens (of nearly the same size) they are more 

 than one half longer and thicker. Nor is the variation 

 in the size of the coxse and femora confined to bred 

 examples. The males, too, vary very much in size. 

 Thus I have one 3 of C. lutea which is 17 lines in 

 length ; the posterior femora are 4 lines long, and 

 nearly 2 lines broad in the middle ; another is 8^ lines 

 long, and the hind femora 2J lines long. 



Synopsis of Species. 



1 (2) Clypeus and pronotum clear yellow, wings yellowish, the fore 



half fuscous throughout ; mesonotum and base of abdomen 

 punctured. Humeralis. 



2 (1) Clypeus and pronotum reddish-yellow or black, wings not fuscous 



throughout in front ; mesonotum not punctured. 



3 (4) Thorax, femora, the base, sides in front, and lower side of abdo- 



men, violaceous. <$ Apex of abdomen black or dull brownish, 

 and with a violet iridescence. Connata. 



Thorax, femora, and base of abdomen not violet. 



5 (6) Pubescence on head, thorax and base of abdomen longish, black, 

 or dark fuscous ; wings with a fuscous fascia in the basal 

 cellule, and a fuscous border at apex. Head and thorax 



A M -D v rarely yell W ' Sylvarum. 



t> (5) .Pubescence on head, thorax and base of abdomen woolly, close, 

 thick, griseous, pale, or yellowish ; wings not marked with 

 fuscous; head, thorax, and abdomen for the greater part, 



