OF WASHINGTON, VOLUME XVIII, 1916 101 



Either there is some variation yet unaccounted for or two forms 

 have been confused. The holotype of mztallicT, and a series from 

 the holotype locality must be studied to decide this point. 



NOTES ON SOME GENERA OF SYRPHIDAE WITH DESCRIPTIONS 



OF NEW SPECIES. 



BY R. C. SHANNON, Bureau of Entomology. 



This paper includes synopses of the genera Chrysogaster and 

 Caliprobola, the latter genus in this country hitherto included un- 

 der Brachypalpus. The kind interest and assistance which Dr. Al- 

 drich and Messrs. Knab, Crawford and Barber have taken in 

 various ways has had much to do with its preparation. The 

 material used is from Dr. Aldrich, Mr. Banks, the Biological 

 Survey and the National Collection. 



Genus CHRYSOGASTER Meigen. 



The genus Chrysogaster in North America can be divided into 

 four distinct groups, as is shown below in the table. Verrall, 1 in 

 his British Syrphidae, has a table which separates the British 

 species into three groups which he designates by their subgeneric 

 names, but the comparison of these groups with our species shows 

 intergrading differences and affinities. Although our groups are 

 distinct, their species are, as a rule, closely allied to each other. 



Loew 2 has described a species, nigrovittata, which has the third 

 antennal joint almost three times as long as broad. This species 

 belongs to the group of which stigmata Will, is typical, as is indi- 

 cated by the wing venation and color of the legs. The writer 

 has seen only one species in this group with antennae as long as 

 Loew described for nigrovittata and this is stigmata (see table). 

 Specimens now in the National Collection which were determined 

 by Williston and recorded in his synopsis of the Syrphidae as 

 nigrovittata are placed by the writer under other species, sinuosa 

 and p'irva, n. sp. Paul R. Jones' records two females of nigrovittata 

 from Idaho. 4 He states that the antennae are a trifle longer than 

 indicated in Loew's description. 



1 Brit. Flies, VIII, p. 186, 1901. 



2 Zeitschr. fur Naturw. XLVIII, No. 14, p. 323, 1876. 



3 Ent. News, 18, p. 238, 1907. 

 4 Ent. News, XVIII, p. 238, 1907. 



