THE CANADIAN ENTOMOLOGIST, 247 



A PRINCIPLE TO OBSERVE IN NAMING GALLS: TWO 

 NEW GALL-MAKING DIPTERA. 



b y w m. h. p a t t o n, hartford, conn. 



CEdaspis-solidago ATRA. 



Ga//s do not differ from those of CE. polita, as described by Osten 

 Sacken (Tr. A. E. Soc. li., 301 ; 1869).- 



This is an addition to the list of gall-making Trypetas given by 

 Osten Sacken in Psyche for April, 1880. I bred both sexes from Solidago 

 galls, Sept. 8, 1875, '" Connecticut. 



Flies. — Female agrees perfectly with Loevv's description of a speci- 

 men from New York. The eyes in the living flies are green, with two 

 longitudinal purple stripes. The shed puparia are left in the galls, and 

 are of a delicate texture and milk-white colour. The New- York speci- 

 mens from which atra was described approach polita in all their points of 

 difference from the Mexican specimens. Whether the Mexican speci- 

 mens belong to the same species is a question which does not concern us in 

 determining the synonomy of atra. If the pale gray border of the wing 

 cross-bands was darkened and one of the bristles on the lateral border of 

 the front was lost (differences which might well arise with increased 

 maturity of the specimens) we should have nothing to separate the 

 species excepting the slightly greater divergency of the second and third 

 bands, and it is probable that this greater divergency would disappear 

 with the blackening of the gray borders. (E. atra is a later name than 

 CE. polita. 

 Cecidomyia-celtis (new genus) deserta, new species. 



Galls are hollow, elongate swellings of young twigs, from which 

 emerge, about the first of June, single Cecidorayian flies from a perfora- 

 tion near the base. Length of gall one half inch to one inch. 



On Hackberry { Celtis occidenialis) ; Orange, Connecticut. 



The name describes the genus. 



This gall I name and describe to illustrate a principle which may be 

 useful in naming galls of which the makers are unknown. It does not 

 seem proper to refer such galls to the genus of plants alone, as was done 

 by the older botanists, nor to the genus of insects alone, as is at present 

 the fashion, but to a combination of the two, thus : Cynips-guercus, 

 Cecidomyia-quercus, Cecidomyia-salix, etc. All Cynips are, it is true, 

 confined to Quercus, but it is the gall and not the insect for which I 



