208 



[September, 



it has no definite posterior margin) certainly does seem to me " semi- 

 circular " in the anthracinus groui:), and suggestive of a " pointed " 

 arch in the other species. Perhaps the following diagrams (fig. 14) 



A. Mesonotum of D. anthracinus. 

 a a the middle lobes. 

 6 b the side lobes, 

 c the scutellmu. 



The dotted lines indicate the posterior 

 outline of the " impres.sion" (Eindruok 

 or Fossa). 



B. Mesonotum of D. ceneus. 

 a a the middle lobes. 

 6 b the side lobes. 

 c the scutellum. 



The dotted lines indicate the posterior 

 outline of the " impression " (Eiudruck 

 or Fossa). 



from photographs of specimens named for me by Konow may explain 

 my view of the character in question. I believe it to be a good 

 character ; but I fear my readers will hardly find it so easy as might 

 be expected from the language of the authors who have pointed it out. 

 Other important, but also somewhat troublesome, characters are to 

 be found in the sculpture of the " vertical area " and tempora. The 

 former is nearly always bounded laterally by furrows or " sutures," 

 which, however visible or even conspicuous in certain lights, arc apt 

 to become quite invisible in others. This fact may explain some 

 puzzling discrepancies in the statements of various authors about the 

 same species : e. g., in nigrntiis (=^ Jissus) . Mr. Cameron says in one 

 place they are " wanting," and in another that they are " almost 

 invisible," whereas Konow separates this very species from fumosus 

 by its having them " sharply defined," and the latest writer on 

 Z)oZe?-«s (Dr. Enslin) calls them "distinct" (deutliche). In all my 

 own specimens they certainly exist, and in some positions are quite 

 conspicuous. Again, one of the surest characters for distinguishing 

 picipes is the presence on each of the tempora of a definite, roundish, 

 polished space, contrasting remarkably with the punctured area sur- 

 rounding it. This character becomes quite unmistakeable, when the 

 light falls on the two smooth spots in a certain way, they then become 

 absolutely dazzling, and could not possibly be overlooked. But in other 

 positions they vanish absolutely, so that a hasty observer might easily 

 fail to find them. Yet, again, the tempora (viewed from above) 



