54 BULLETIN 82-6, TJ. S. DEPARTMENT OF AGRICULTURE. 
2. Cornicles cylindrical at base and extremity; abruptly swollen in middle. . 
Rhopalosiphoninus. 
Cornicles with the swelling gradual 3. 
3. Head with a large central process on vertex Francoa. 
Head without this 4. 
4. Antennal tubercles large and diverging 5. 
Antenual tubercles converging; head and basal antennal segments with 
very prominent capitate hairs Capitophorus. 
5. Cornicles much longer than cauda which is somewhat tapering. . Amphorophora. 
Cornicles about the length of cauda which is usually constricted near its 
base Megoura. 
6. Cornicles very small, much smaller than the long, broad cauda. .Hyalopteroides. 
Cornicles as long as or longer than the cauda 7. 
7. Head with prominent, elongate projections to the antennal tubercles, par- 
ticularly evident in the apterous form Phorodon . 
Head without these 8. 
8. Tubercles strongly converging Myzus. 
Tubercles distinctly diverging 9. 
9. Cornicles thick, about as long as the cauda which is large and somewhat 
constricted near base " Macrosiphonella. 
Cornicles very long, rather slender, subcylindric, somewhat tapering 10. 
10. Cauda elongate, constricted near base Macros! phum. 
Cauda moderate or elongate, not constricted near base 11 . 
11. First antennal segment and abdominal segments with long fingerlike tuber- 
cles in the apterous form Acanthaphis. 
Without these Illinoia. 
Genus ACANTHAPHIS Matsumura. 
Plate VII, R-TJ. 
1918. Acanthaphis Matsumura, Trans. Sapporo Nat. Hist. Soc., v. 7, pt. 1, p. 15. 
The genus Acanthaphis Mats, is somewhat related to Phorodon. 
Characters. — Head with prominent diverging antennal tubercles. Antennas of six 
segments, first segment with a long fingerlike projection in the apterous form. Corni- 
cles long, slender, and cylindrical. Cauda elongate, conical. Dorsum of abdomen 
with long fingerlike tubercles. Body with capitate hairs. 
Type (fixed by Matsumura, 1918), Acanthaphis rubi Mats. 
Genus AMPHOROPHORA Buckton. 
Plate IV, A, B. 
1876. Amphorophora Buckton, British Aphides, v. 1, p. 187. 
1886. Macrosiphum Oestlund, Minn. Geol. Survey Rept. 14, p. 27. 
1900. Macrosiphum Del Guercio, Nuove Rel. Staz. Firenze, ser. 1, no. 2, p. 159. 
1901. Ncctarosiphon Schouteden, Ann. Ent. Soc. Belg., v. 45, p. 112. 
1913. Eunectarosiphon Del Guercio, Redia, v. 9, p. 188. 
1913. Rhopalosiphum Van der Goot, Tijd. voor Ent., v. 56, p. 146. 
Buckton erected his genus Amphorophora for his amjmllaia which 
he had secured in the apterous form only. Oestlund gave the generic 
name Macrosiphum to a species he described as rubicola. In his sec- 
ond paper Oestlund describes a species under the name ampullata 
Buckton and says: 1 "The length of the antennae, together with the 
distinct frontal tubercles, may justify our exception of Ampho- 
rophora as a good genus. 7 ' In speaking of his Macrosiphum 
» Bui. 4, Geol. and Nat. Hist. Surv. Minn., p. 77, 1887. 
