GENERIC CLASSIFICATION OF APHIDIDAE. 45 
short, subcylindrical ; cauda somewhat conical, not quite as long as the cornicles; anal 
plate rounded. Tarsi atrophied in all the forms. 
Type (monotypical) , Atarsos grindeliae Gill.. 
Genus BRACHYCOLUS Buckton. 
Plate VI, T, U. 
1879, Brachycolus Buckton, Mon. British Aphides, v. 2, p. 146. 
1913. Brachysiphum Van der Goot, Tijd. voor Ent., v. 56, p. 105. . 
The genus Brachycolus was erected with stellariae Hardy as type 
and is easily recognized from the structure of the cornicles. Van 
der Coot's genus is in all essential respects the same, the type of that 
genus being ihalictri Koch. 
Characters. — Head without prominent antennal tubercles. Antennae of six segments 
and armed with subcircular sensoria. Wing venation normal.- Cornicles verysmall> 
especially in the apterous form. Cauda medium in size and conical. Body elongate; 
legs and antennae usually short. 
Type (monotypical), Aphis stellariae Hardy. 
Genus BREVICORYNE V. d. Goot. 
Plate VI, J, K. 
1915. Brevicoryne Van der Goot, Beitrage z. Kennt. d. Holl. Blattlause, p. 245. 
1916. Oedisiphum Van der Goot, Zur Kenntniss der Blattlause Java's, p. 122. 
1918. Brevicoryne Das, Mem. Ind. Mus., v. 6, p. 179. 
The genus Brevicoryne was erected with Aphis brassicae L. as type, 
a species in which the cornicles are very short and somewhat swollen 
in the middle, and the cauda conical. In the species Oedisiphum. 
compositarum V. d. Goot quite similar characters are found. The 
cornicles appear to be somewhat more slender but in the main the 
species appear alike. Oedisiphum, therefore, becomes a synonym. 
Characters. — Head without prominent antennal tubercles; antennse of six segments 
and armed with subcircular sensoria. Wing venation normal. Cornicles short, not 
much longer than the cauda and swollen in the middle. Cauda short and broadly 
conical. 
Forms not especially elongate. 
Type (monotypical), Aphis brassicae L. 
Genus CAROLINAIA Wilson. 
Plate VI, V, W. 
1911. Carolinaia Wilson, Can. Ent., v. 43, p. 61. 
The genus Carolinaia Wilson is related very closely to Rhopalosi- 
phum. In fact some of the species placed here are distinguished 
from members of that genus only by the fact that the cubitus is 
lacking in the hind wing. It is true that the type species was 
described as having five-segmented antenna in the apterous form. 
But other species, like this in all other respects, have normal six- 
segmented antennas. Certain species of Rhopalosiphum will show 
strains in which nearly all of the individuals will have five-segmented 
antennse and yet the normal antenna for such species is a six- 
segmented one. In this closely related genus, therefore, it is not 
surprising if a similar condition is met with. 
