1908] ROHWER — THE APHID GENUS FORD A 67 



EXPLANATION OF PLATE. 



Fig. \. Alepomyia bryanti, genitalia, d*. 



Fig. 2. Alepomyia bryanti, venation. 



Fig. 3. Holocentropus flaviis, genitalia, 6^ 



Fig. 4. Limnephilus moostus, genitalia, P . 



Fig. 5. Limnephilus pulehellus, genitalia, c?. 



Fig. 6. Polycentropus maculatus, genitalia, d^. 



Fig. 7. Isoperla ventralis, venter, 9 . 



Fig. 8. Limnephilus moestus, genitalia, d^, top. 



Fig. 9. Limnephilus pulchellus, genitalia, c^, top. 



Fig. 10. Limnephilus moestus, genitalia, d^. 



Fig. 11. Limnephilus moestus, genitalia, d^, top. 



Fig. 12. Halesus sparsus, genitalia, d^. 



Fig. 13. Alepomyia bryanti, genitalia, d^, top. 



Fig. 14. Anabolia quadrinotata, genitalia, d*. 



THE APHID GENUS FORDA. 



BY S. A. ROHWER, BOULDER, COLORADO. 



Last spring Prof. T. D. A. Cockerell sent some aphids of the genus Forda and 

 some ants to the U. S. Nat. Mus. The ants were named Lasius suhnicjer Emery 

 while the aphids were supposed to be a new species. They were determined by 

 Mr. Pergande. Mr. Pergande did not care to describe the aphids so I undertook 

 to collect some more of them and work them out, however I was not able to find the 

 same species, but found two others that are thought to be new to science and are 

 herein described. There are but five representatives of this genus known from 

 North America. One {F. kingii W. P. Ckll.) from Massachusetts, one {F. occi- 

 dentalis Hart.) from Illinois, one (F. interjecti W. P. Ckll.) from New Mexico and 

 the two new species from Colorado. 



The work is a contribution from the laboratory of Systematic Zoology of the 

 University of Colorado. I am greatly indebted to Prof. T. D. A. Cockerell for many 

 suggestions. 



The tyjDes of the new species have been sent to the U. S. Nat. Mus. 



The following table will separate the North American species. 

 Second and fourth antennal joints not equal, fourth longer; antennal formula 

 3 (45) 21 ; color pale green, body covered with fine hair (111.) occidentalis Hart. 



