1122 The Zoologist— March, 1868. 



4. M. Lychnidis, Koch. — Passerini excludes the synonyms which 

 Koch has recorded of this species, and observes that the Aphis 

 Lychnidis of authors has perhaps been sometimes confused with it, and 

 that it differs from A. Lychnidis, Kaltenbach, not only in its generic 

 characters but also in the wholly black colour of the winged viviparous 

 female. This is also a matter for examination. The comparative 

 length of the nectaries appears to be uncertain as a specific cha- 

 racter. 



5. M. OxijacaniluB, Koch. — Passerini observes that this is not the 

 Aphis Oxyacanthse of Schrank. 



6. M. Tanaceti, Linu. — Passerini remarks that this is the Siphono- 

 phora Tanaceti of Koch, and partly the species which I have 

 described as Aphis Absinthii, but I believe that all the specimens 

 which I have noticed of the latter species are quite distinct from the 

 S. Tanaceti of Koch. 



7. M. Plantagineus, Passerini. — On Plantago media. Not recorded 

 as British. 



8. M. tetrarhoda. Wlk. — Siphonophora Rosarum, Koch. 



9. M. Ribis, Linn. 



10. M. Asclepiadis, Passerini. — Not recorded as British. 



11. M. Lylhri, Schrank. 



12. M. Mahaleb, Fonscolombe. — Passerini conjectures that I have 

 combined this species with Phorodon Humuli, from which it differs in 

 the frontal tubercle not being dentate. He observes that the vivi- 

 parous winged females appear suddenly on Prunus Mahaleb in 

 October, and inquires "from whence do they come ?" 



Of the preceding twelve species Plantagineus, Tetrarhoda, Ribis, 

 Asclepiadis, Lythri and Mahaleb should be separated from Myzus, and 

 it is doubtful whether Oxyacantha; and Tanaceti belong to it. 

 Tetrarhoda and Ribis are much more allied to the genus Phorodon. 



Genus 5. Hyalopterus, Koch. 



A. Viviparous apterous female more or less powdered with white. Abdomen 

 of the viviparous winged female green, with three deeper green 

 stripes. 

 A. Apterous viviparous female thickly powdered. Tail green. . . 1. Pruni. 

 AA. Apterous viviparous female slightly powdered. Tail brown. 2. Arundinis. 



AA. Apterous viviparous female never powdered. Abdomen of the viviparous 

 winged female luteous-green, most often with dorsal black bands and 

 with marginal black points 3. trirhoda. 



