The Zoologist— March, 1868. 1121 



A. Viviparous apterous female wholly black or brown. 

 A. Tail more or less long, never very small. 



A. Nectaries long, cylindrical, more lhan twice longer than the tail. 1. Cerasi. 

 aa. Nectaries short, a little thicker at the base, hardly longer than the 



tail. .2. Pyrarius. 



A A. Tail very small or none. 



a. Viviparous winged female with a reddish abdomen. Stigma and 



veins whitish. . 3. Persicce. 



aa. Viviparous winged female with a black abdomen. Stigma and veins brown. 

 a. Body black, shining. Stigma black. .... 4. Lych'nidis. 

 aa. Body brown, dull. Stigma pale, or slightly brown. . 5. Oxyacanlhce. 

 AA. Viviparous apterous female never black or brown. 



A. Apterous female with a rust-coloured abdomen and with a large black 



dorsal spot. 6. Tanaceli. 



AA. Apterous female wholly green, or whitish green, or luteous lemon-colour, 

 or ochraceous. 

 a. Viviparous winged female with a brown abdomen. Apterous female 



whitish green. 7. Plantagineus. 



aa. Viviparous winged female with the abdomen never brown. 



a. Apterous viviparous tuberculale-setose above. Bristles capitate. 



8. telrarhoda. 

 aa. Apterous viviparous female not tuberculate-setose. 



* Antennae longer than the body. 9. Ribis. 



** Antennas shorter or not longer than the body. 



f Body orange-colour 10. " Asclepiadis. 



ff Viviparous apterous female green. 



% Nectaries very long. Stigma gray. . . . 11. Lytkri. 



XX Nectaries moderately long. Stigma greenish. . . 12. Mahaleb. 



1. M. Cerasi, Fabr. — In this vicinity, during 1866, M. Cerasi 

 appeared in June and passed away in August, and reappeared in the 

 middle part of October, when the male, which has not yet been 

 described, was of frequent occurrence. The latter month is generally 

 the season for the second especial swarming of Aphides, and is the 

 time in which they should be more particularly observed, in order to 

 determine what are permanent species and what are annual or 

 apparent species, or are modified by the agency of the plants on which 

 they feed and pass away without attaining the last state, and in 

 following years are replaced by other forms whose peculiarities are 

 also owing to their food and to local circumstances. 



2. M. Pyrarius, Passerini. — Not recorded as British. 



3. M. Persicce, Passerini. — The characters by which Passerini dis- 

 tinguishes this species from Aphis Persicae, Fonscolombe, will be 

 noticed in the sequel. 



SECOND SERIES — YOL. HI. 



