360 THE CANADIAN ENTOMOLOGIST 



of whose actions are reducible to chemotropic responses.*** The 

 most trival movements may have the deepest significance for the 

 individual, and, when repeated regularly under certain conditions, 

 they have the value of tropistic reactions. It is well not to forget 

 that the record of a vital act is less easy to couch in critical terms 

 than is the description of an inert form. There are several factors 

 which influence behaviour, such as the nature of the species, the 

 susceptibility of the individual, the place and time of observation. 

 If for any reason, known or unknown, the behaviour is inde- 

 terminate, we can do nothing with it and the result of observation 

 is negative. Indeed the interaction of tropisms may so confuse 

 the issue as to render observation nugatory. It is only under the 

 fortunate train of circumstances which permits straight and clear- 

 cut reactions, several times repeated, that the study of behaviour 

 becomes available for synthetic treatment. 



NOTES ON NOVA SCOTIAN EUPTERYID LEAF- 

 HOPPERS INCLUDING DESCRIPTIONS OF 

 TWO NEW SPECIES. 



BY W. L. MCATEE, WASHINGTON, D. C. 



Professor W. H. Brittain, Provincial Entomologist of Nova 

 Scotia, sent the writer a small collection of leaf-hoppers of this 

 group, which is herewith reported upon, chiefly for the reason that 

 characterization of two new species is required. 



List of Species. 



Dikraneura mali Provancher. — Truro, August 26; Digby 

 County. 



Empoasca atrolabes Gillette. — Kentville, July 3; Annapolis, 

 July 15. 



Empoasca ohtusa Walsh. — Kentville, August 14, 16; Annapolis 

 Co., August 8, 11, 28. 



Empoasca unicolor Gillette. — Annapolis Co., August 11. 



Typhlocyba cymba, new species. — Head and thorax pale 

 yellow flecked with pellucid greenish yellow ; elsewhere pale yellowish 



***N. E. Mclndoo: Recognition Among Insects. Smithsonian Misc. Coll., 

 vol. 68, No. 2, Washington, 1917. 

 November. 1918 



