McAtee — Membracidae of the Vicinity of Washington, D.C. 131 



In connection with the genus Vanduzea, it should be mentioned that V . 

 vestita Goding was described (Catalogue, 1894, pp. 440-441) from Arizona 

 and District of Columbia. Goding notes "Type in author's collection," a 

 collection now in the National Museum. A specimen there labelled Type 

 of Vanduzea vestita Goding, Washington, D. C. 9.4.81, is, as would be 

 expected, a male of V. arquata Say. Thus if we follow the method of 

 specific types we must consider V. vestita Goding a straight synonym of V. 

 arquata Say. If this specimen is not really the type or if we ignore the type 

 system of identifying species, the name vestita would be available for the 

 western form most closely related to arquata. This has recently been 

 called V. triguttata Burmeister, probably without positive identification. 



Following is a key worked out by the writer in an endeavor to get a 

 better understanding of the species of Vanduzea. More work needs to be 

 done particularly on the forms now lumped as segmentata Fowler. 



A. Pronotum neither pinched-in nor angulate-compressed at any point. 

 B. Length 4.5-6 mm. ; sexes very different in size and coloration, 



males blackish, females brownish arquata Say. 



BB. Length 3-4.5 mm.; sexes of about the same size and color, 



blackish (?) triguttata Burmeister. 



AA. Pronotum angulate-compressed posteriorly. 



C. Pronotum gibbous above eyes, the latter not promi- 

 nent as seen from above ; pronotum angulate-com- 

 pressed for the posterior third of its length. 



segmentata Fowler. 

 CC. Pronotum sloping backward above eyes, the latter 

 prominent as seen from above ; pronotum angulate- 

 compressed for the posterior half of its length. 

 D. Dorsal outline of pronotum with a distinct 

 sinuation at middle which together with 

 the pronounced pinching-in at the same 

 point gives the pronotum a strongly bi- 



vesicular appearance bajula Goding. 



DD. Dorsal outline of pronotum without distinct 



sinuation at middle laeta Goding. 



ENTYLIA Germar. 



A. Anterior division of pronotal crest broad, considerably higher than 

 posterior, its anterior outline distinctly angulate; color usually 



pale concisa. 



AA. Anterior division, narrower, but little higher than posterior, its 



anterior margin merely sinuate; color usually dark sinuata. 



E. concisa Walker. — Common and widespread; season May 9 to Sept. 

 29. P. I. 



E. sinuata Fabricius.— Much less abundant than the preceding species, 

 but as widely distributed; dates of collection range from April 28 to Oct. 

 27. P. I. 



