ART. 20 THE APHID GENUS AMPHOROPHOEA MASON 5 



cornicles. In Megovra they are practically the same thickness from 

 the base to the center, after which they narrow to the flange. This 

 often gives the center the appearance of a slight bulge. In Amphor- 

 ophora the cornicle narrows considerably between the base and the 

 swollen central portion, giving an actual, conspicuous dilation. 



In the tables of measurements the first line for each specimen refers 

 to the left side, such as left antenna or left cornicle. 



When a species is described from one specimen only, this speci- 

 men is designated as the type. 



When a species is described from several specimens, all from the 

 same colony, these specimens are designated as cotypes, and there 

 is no type. 



When a species is described from several specimens taken from 

 different colonies, either in the same or different localities, the speci- 

 mens from one colony are designated as cotypes, those from the 

 other colonies as paracotypes. 



The following keys will help to separate the species. It has been 

 necessary to omit hetae from the keys as no specimens were avail- 

 able for study and the published description does not give sufficient 

 details. 



KEY TO ALATE VIVIPAROUS FEMALES ' 



1. Cornicles distinctly reticulated 2 



Cornicles not reticulated, often imbricated at tip 15 



2. Cornicles shorter than segment III of antennae 3 



Cornicles equal to or longer than segment III 11 



3. Segment III of antennae light colored corylina (Davidson). 



Segment III of antennae dark colored 4 



4. Segment IV longer than V 5 



Segment IV shorter than V 10 



5. Cornicles not longer than width of head through eyes 6 



Cornicles considerably longer than width of head through eyes 8 



6. Segment IV with sensoria brittenii (Theobald). 



Segment IV without sensoria 7 



7. Cauda with about six lateral hairs. Cornicles very broad. 



essigwanai, new name. 

 Cauda with about two lateral hairs. Cornicles more slender (On Acon- 

 itum) aconiti (v. d. Goot). 



8. Ill with a row of about 16 sensoria vaccinii, new species. 



Antennae with numerous senoria 9 



9. V with 14-15 senoria hayhursti, new species. 



V with 5-10 sensoria mitchelli, new species. 



10. Smallest diameter of cornicle one-half of widest diameter (On Spiraea). 



spiraecola (Patch). 

 Smallest diameter of cornicle two-thirds of widest diameter (On Rubus). 



reticulata, new species. 



11. IV with sensoria brittenii (Theobald). 



IV without sensoria 12 



•■^ Roman numerals refer to tlie number of the segment of the antenna, as segment III. 



