714 Pomona College Journal of Entomology 



because of the loose characterization of the genera. Because of tlie past complica- 

 tions, I have accepted the revision as proposed by Prof. Wilson and in attempting 

 to place new species found it necessary (and I believe the characters of the species 

 necessitate it) to form three new genera. 



In examining the key it will be seen that the principal characters for separ- 

 ating the genera are the comparative lengths of the spur of the antennal article 

 VI with the base, the length and shape of the cornicles, and the length and shape 

 of the style, all characters which are perhaps the most constant in this tribe. 

 There are but five genera represented as follows: Arctaphis Walker, Chaitophorus 

 Koch, Symdohitis Mordwilko, Thomasia Wilson, and Sipha Passerini. To these, 

 I have added the following new genera: FAchochaitophorus, Micrella and Fulla- 

 waya. If I accepted Wilson's classification at all I found that I could not place 

 Micrella in the genus Thomasia because of the longer spur of antennal article VI ; 

 it was impossible to place it with Arctaphis because of the shape of the style; it 

 is certainlj' an intermediate between these two. Eichochaitophorus, because of the 

 shorter antennal spur, cannot be placed with Arctaphis, though the style is of the 

 same general character. This might have been overlooked, had it not been that 

 the species described has a very distinct, constricted anal-plate which seems to 

 place the genus somewhere between the present genus Arctaphis and the genus 

 Callipterus. The long stipe of the style is different from that of the former, and 

 in consideration of all the characters, I could not find a place for it in any of the 

 older genera, so created the new one. FtiUawaya is a splendid new genus, com- 

 bining to a remarkable degree characters of several widely separated genera. The 

 body, in shape and construction, resembles greath' some of the species of Aphis, 

 while the lack of cornicles suggests some other genera. The general clothing of 

 hair is as in this tribe. The feeding habits differ from all other members of the 

 tribe, so far as I know, this being a root and subterranean form rather than an 

 aerial and leaf- or bark-eating form. It falls just between Sy7ndohius and 

 Thomasia, though it is widely different from either. 



According to the following Key to Genera and Species it will be seen that 

 nearly all of the Eastern Chaitophorus fall in the new genus Thomasia and into 

 this genus also fall the species recently described by me as Chaitophorus salici- 

 cola (P. C. Jr. Ent. Ill, p. 534, 1911). Also into this new genus fall Ch. populi- 

 foliae Fitch, Ch. negundinis Thomas, Ch. viminalis Alonell (thougli this is some- 

 what difficult to handle because of the varied forms and contradictory descrip- 

 tions), and a new species, crucis, described in this article 



Provisional keys to the |)rcsent known genera and to tlic taliforiiia species 

 are as follows: 



Key ti> Genera 



1. Antenna- six articled 2 

 Antennae five articled. 8 



2. Spur of article VI at least tliree times as long .is the base. 3 

 Spur of article VI not three times as long as the base. 6 



3. Spur of article VI not more than five times as long as the base, cor- 



nicles not longer than the base. 4 



