110 Bulletin of the Brooklyn Entomological Society Vol. XII 



to each other, from which I surmise that they seek mates from 

 some other brood. When dayhght comes they try to hide, put- 

 ting their head into any dark corner, where they remain all day 

 without motion. 



The males and females are easy to distinguish by the characters 

 given in Horn's description but I note a further sexual character 

 in the granulation of the elytra; in the males the lateral margin 

 and the tip behind the tubercles is smooth, while in the females 

 this area is distinctly granulated. Also a slight difference in the 

 shape of the thorax, that of the males being broader. The males 

 also have a more shining black appearance than the females. 



I have now thirty-six specimens of Dinapate wrightii, fourteen 

 males and twenty-two females. I can still hear the second brood 

 at work and hope to have more emerge next year. 



A KEY TO THE SPECIES OF THE GENUS CERESA A. & S. 

 OCCURRING NORTH OF MEXICO AND THE DESCRIP- 

 TION OF A NEW SPECIES (MEMBRACID^: 

 HOMOPTERA). 



By Edmund H. Gibson and Emma Wells, U. S. Bureau of Entomology. 



To the novice the genus Ceresa represents a very puzzling 

 group of insects of the family known as tree-hoppers, and even 

 to the systematist it has its difficult problems. From the study 

 of specimens in the U. S. National Museum and material gen- 

 erously loaned by Mr. W. D. Funkhouser the authors have been 

 able to establish the following key to the species. In offering it 

 as a guide in the identification of species it must be stated that 

 it is nearly impossible to make determinations without having at 

 hand a goodly series of specimens and a collection of all the 

 members of the genus, to be used for comparison. 



Ceresa was described by Amyot and Serville in 1843. The 

 logotype of the genus is vitulus Fabr. Ceresa may be distin- 

 guished from Stictocephala Stal, its closely allied genus in North 

 America, by having the pronotum distinctly armed with supra- 

 humeral horns and the metopidium acutely angled. The forma- 



