198 U'cbruiiiy, 



In E.palustre, however, they do materially check the growth of 

 the plant, lessening the distance between the joints, and distorting the 

 upper part of the plant into a confused mass of leaves and blossoms, 

 in which several galls often become confluent, while the energy of the 

 plant is thrown into side shoots, which run up like long arms raised 

 above the bunch of a head. 



In E. parvijlorum the attacked joints formed a thick mass of about 

 half-a-dozen confluent galls, upon which the natural silky pubescence 

 of the plant was strongly developed. 



Haslemeut.. 



AN ESSAY TOWARDS A KNOWLEDGE OF BRITISH HOMOPTEBA. 

 BY THE EEV. T. A. MAESHALL, M.A. 



{Continued from ijage 155). 



Gen. DELPHAX, Fab. 



This genus is rich in species, which my own unassisted efforts have 

 hitherto failed to bring together. Mr. Walker's catalogue enumerates 

 20 ; Flor has described 29 ; and Stal (Ofv. af Sveriges Delphax-arter) 

 gives 35 indigenous to Sweden. The other principal authorities are 

 Boheman, Grermar, and Dahlbom. From these sources I have suc- 

 ceeded in identifying only 17 British species, to which I anticipate 

 considerable additions in future seasons. The Greek word " Delphax " 

 means a young pig, a porker, and the specific names should be masculine ; 

 they have the feminine termination in most authors, probably owing to 

 their transference from the genus Fulgora. Their identification is no 

 easy matter, owing to (1) the meagre descriptions of authors, (2) the 

 disparity between the sexes, and (3) the fact that an apterous form 

 with abbreviated elytra frequently co-exists with those more fully de- 

 veloped ; so that an acquaintance with no less than fo\xr different kinds 

 of individuals is necesssry to complete the knowledge of one species. 

 These imperfectly fledged adults have no doubt been frequently passed 

 over by collectors as mere pupae. The insects are found abundantly on 

 various grasses and rushes, and for the most part in damp situations. 

 The eggs, at leasi> of several, are hatched in the aiitumn ; and extremely 

 minute larvae may be detected at all times during the winter at the roots 

 of the plants whose juices they suck. A synoptical view of the species 

 is subjoined. 



