348 Annals Entomological Society of America |Vol. VIII, 
contraction or misprint of A phidioides which was also previously 
used in the Hemiptera and must, therefore, give way to Ptero- 
comma, provided by Buckton for his species pilosa, and which 
the writer believes is the same as A phis populea Kalt. Previous 
to the establishment of this genus Buckton used Melanoxanthus 
to cover Aphis salicis of Linnaeus and this name would be 
valid if it had not already been used in the Coleoptera. 
Schouteden 1906 uses Melanoxantherium in place of Melanox- 
anthus, but the writer is of the opinion that Melanoxanthus 
falls before Pterocomma. Kirkaldy provides the name 
Aristaphis in place of Cladobius and A phioides, apparently 
considering these names to be preoccupied. 
The synonomy of the genus would then read: 
Pterocomma Buckton. 
A phioides Passerini. 
Cladobius Koch. 
Melanoxanthus Buckton. 
Melanoxantherium Schout. 
Aristaphis Kirkaldy. 
Characters of the tribe and genus. 
Antenne with six segments and reaching to near the base 
of the abdomen. Wings normally with venation as in Aphis. 
Nectaries short, but clavate. Cauda short and broadly rounded 
at the tip as in Lachninit. Entire body, antenne and legs, 
covered with long hairs as in the Lachnini. As has already 
been pointed out by Oestlund, this group appears intermediate 
between the Chaitophorini and the Lachnini. Their habits 
and actions being in different ways similar to both. 
A Key TO THE SPECIES.* 
1. Nectaries with diameter of opening at tip not greater than the smallest part 
Of theme cranes. 27 5.05 tle he asada aes Re CR ae ne 3 
2. Nectaries with diameter of opening at tip greater than the smallest part of 
thewmec tary hs Ao See a rah ee akc a ey eae REN + 
3. Distal end of nectaries abruptly constricted to a small opening; flange wanting 
P. flocculosa 
Distal end of nectaries not abruptly constricted. Nectary swollen in the 
middle and tapering to a small opening at the tip. Light flange present... . 
P. salicis 
4. Nectaries short and stout, length not more than twice the greatest diameter 
P. smithiz 
Nectaries more than twice as long as the greatest diameter. 
5. Nectaries clavate and twice as long as the hind tarsi............ P. bicolor 
Nectaries appearing cylindrical or clavate and about equal in length to the 
Wana, BARST ATS yok a ua cotta Mocataal hobs con OO oko AL: ened Re ae P. populea 
*Prof. C. P. Gillette, of the Colorado Agricultural College, kindly assisted in 
the preparation of this key. 
