with Prof. F. M. Webster, who has also reared these two species, 

 as well as a third, and as his views correspond with the writer's, a 

 table has been drawn up, after careful comparison of nearly a 

 hundred examples of the first two species discussed and a lesser 

 number of the third. 



"As a preliminary, it should be stated that the writer fully 

 concurs in the views expressed by Dr. Horn* when he stated thai 

 the table furnished at that time, 1878, although founded on 

 color characters, attained 'the object in view as nearly as can 

 be done'; also that the species were so variable, even with the sup- 

 pression which he had made, 'as almost to resist generalization'. 

 "The first two forms considered can readily be distinguished 

 by color characters alone, examination of all available ma- 

 terial showing these colors of sufficient constancy to leave no 

 doubt as to the specific identity of a single specimen. More- 

 over, the three species are physiologically distinct, being con- 

 stant within certain limits as regarding habits, 0. bimaculata 

 having thus far been reared only from canes of raspberry 

 and blackberry (Rubus), 0. trijpunctata from various deciduous 

 trees, including dogwood (Cornus) and witch-hazel, while the 

 third species is known only as inhabiting the elm {Ulmus). 

 The three species now under discussion may be separated by the 

 aid of the following table: 



A. Ventral surface (including legs and antennas) excepl 

 thorax, black; abdomen somewhat coarsely and \m\\ 

 sparsely punctate, with rather long, black or dark 

 brown pubescence. 



Elytra with black pubescence, disc with prominent 

 carinas, and deeply and closely punctate. 

 Head somewhat strongly and denselj punc- 

 tate, with moderately black, brown, or darkyel- 



low pubescence bimaculata Oliv. 



AA. Ventral surface (including legs) Largely yellow: ab- 

 domen with punctuation feeble, obsolete, orwanting 

 on some segments; pubescence short and pale. 



*Loc. cit. 



