44 BULLETIN 826, IT. S. DEPARTMENT OF AGRICULTURE. 
The genus Myzoaphis was erected by Van der Goot with Aphis 
rosarum Kalt. and Aphis abietina Walker. These two species show 
practically no antennal tubercles and are very little different from 
a typical Aphis, excepting in the clothing of the antennse and body. 
The cauda as figured by Van der Goot is quite conical, but the 
writer's specimens are somewhat different from this and specimens 
of abietinus do not show a cauda exactly like his figure. In fact, 
they appear more like an Aphis. This genus, therefore, should not 
be separated or it will necessitate the separation of very many 
other forms under new names. 
Characters. — Head without prominent antennal tubercles. Antennse of six seg- 
ments and armed with subcircular sensoria. Fore wings with the media twice branched ; 
hind wings with both media and cubitus present. Cornicles cylindrical or slightly 
tapering. Cauda usually not as long as the cornicles, subcortical, rather elongate, 
constricted about the middle. Anal plate rounded. Males usually winged, oviparous 
females apterous. 
Type (by suspension of rules), Aphis sambuci L.. 
Genus ASPIDAPHIS Gillette. 
Plate VI, L-O. 
1917. Aspidaphis Gillette, Can. Ent., v. 49, p. 196. 
The genus Aspidaphis appears to be related both to Cavariella 
and to Vesiculaphis. It has the short, blocky form of Vesicul aphis 
and also the peculiar integument. On the other hand, certain species 
with a similar integument are met with in Cavariella. The develop- 
ment of the dorsal abdominal tubercle is here very pronounced and 
the cornicles have taken on a peculiar shape. 
Characters. — Head without prominent antennal tubercles; antennae short, of rive 
segments, armed with subcircular sensoria. Wing venation normal. Cornicles very 
small, somewhat swollen near the distal extremity and with the opening in the side of 
the cornicle, not at the tip. Abdomen with a dorsal caudal tubercle developed into 
a large conical process extending beyond and fully covering the cauda in the apterous 
form. Body elongate. 
Type (monotypical), Aspidaphis polygonii GilL 
Genus ASIPHONAPHIS Wilson & Davis. 
1919. AsiphonapMs Wilson & Davis, Ent. News, v. 30, p. 39. 
Characters. — Head without prominent antennal tubercles. Antennas of six segments 
armed with subcircular sensoria. Fore wings with the media twice branched; hind 
wings with both media and cubitus present. Cornicles absent entirely. Abdomen 
with large lateral tubercles. Cauda somewhat conical or Aphis-like. Anal plate 
rounded. 
Type (monotypical), Asiphonaphis pruni Wilson & Davis.. 
Genus ATARSOS Gillette. 
Plate vi, r-s. 
1911. Atarsos Gillette, Ent. News, v. 22, p. 440. 
Characters. — Head without prominent antennal tubercles. Antennae of six segments 
armed with subcircular, somewhat tuberculate sensoria; fore wings with the media 
twice branched, hind wings with both media and cubitus present. Cornicles rather 
