30 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. 



Characters. — Cornicles truncate without a very distinct neck; antennas of six 

 segments armed with a few minute bristles and oval or subcircular sensoria. Fore 

 wings with the media twice branched ; hind wings with both media and cubitus present. 

 Cauda knobbed; anal plate bilobed, not divided; body usually with stout hairs. 



Type (fixed by Passerini, i860), Aphis coryli Goetz. 



Genus SYMYDOBIUS Mordwilko. 



Plate IV, DD, EE. 



1S94. Symydobius Mordwilko, Varshava TJniversitetskiia Izviestiia, v. 8, no. 58, p. 65. 

 1917. Yezocallis Matsumura, Jour. Coll. Agr. Tohoku Univ., v. 7, pt. 6, p. 369. 

 Symdobius of later authors. 



The genus Symydobius Mord., which was erected for ohlongus 

 Heyden, has often been spelled Symdobius by subsequent writers. 

 This is probably due to the erection of the genus in a Russian publi- 

 cation which is available to few workers, at least in this country. 

 Specimens of this species studied were collected by Mordwilko at 

 Petrograd and Warsaw and by Schouteden at Brussels. The species 

 which passes under the name of ohlongus in America is quite distinct, 

 as has been pointed out by the writer. 



Characters. — Cornicles present, truncate or with an evident neck and on a broad 

 low base. Antennae of six segments armed with numerous delicate hairs, sensoria 

 somewhat oval or subcircular; sensorium at the base of the unguis not long and nar- 

 row, with a fringe but without a prominent one, cauda semicircular, anal plate similar 

 in shape, sometimes slightly indented. Fore wings with the media twice forked; 

 hind wings with both media and cubitus present, somewhat separated at the base. 



Type fmonotypical), Aphis oblonga Heyden. 



Subtribe SALTUSAPHIDINA. 



The subtribe Saltusaphidina is separated from the other related 

 ones principally on the nature of the head. The most important 

 character, possibly, is the structure of the eyes, in which the ocular 

 tubercles appear to be wholly lacking. 



Characters. — Forms living usually in damp places upon the foliage of sedges and 

 grasses, narrow elongate bodies, eyes with ocular tubercles lacking, legs often modi- 

 fied for leaping. Oviparous forms apterous, somewhat similar to the viviparous 

 forms, producing several eggs. 



Key to the Genera op the Saltusaphidina. 



Head considerably elongate, cornicles cup shaped, legs modified for leap- 

 ing Saltusaphis. 



Head not much elongated, cornicles mere rings, legs not modified for leap- 

 ing Thripsaphis. 



Genus THRIPSAPHIS Gillette. 

 Plate IV, X. 

 1917. Thripsaphis Gillette, Can. Ent., v. 49, p. 193. 



The genus Thripsaphis was separated from Saltusaphis for balli 

 Gillette, which the present writer had included in that genus, and 

 certain other similar species. 



