GENERIC CLASSIFICATION OF APHIDIDAE. 71 
Genus PACHYPAPPELLA, n. n. 
Plate XI, H-M. 
1909. Pachypappa Tullgren, ArMv for Zoologi, Bd. 5, no. 14, p. 69. 
In 1854 the genus Pachypappa was erected by Koch with marsu- 
pialis and vesicalis in the genus. A study of marsupialis shows that 
this species is in reality a Pemphigus as it shows all the characters of 
this genus. Tullgren, 1909, noted this and therefore interpreted the 
genus differently. Marsupialis had, however, been set as the 
type of the genus. Pachypappa Koch, therefore, becomes a syno- 
nym of Pemphigus, and Pachypappa Tullgren must receive a new 
name for which Pachypappella is here given. 
Charactws. — Stem mother without cornicles but with wax plates; antennae five- 
segmented. Alate form with cornicles; antennse six-segmented and with transverse 
sensoria. Fore wings with media once branched, hind wings with both media and 
cubitus present. 
Type (present designation), Pachypappa lactea Tullgren. 
Genus PEMPHIGUS Hartig. 
Plate XI, N-U. 
1837. Pemphigus Hartig, Jahresb. u. d. Fortschr. d. Forstwiss. und forstl. Naturk., v. 1, p. 645. 
1839. Byrsocrypta Haliday, Ann. Nat. Hist., v. 2, p. 190. 
1840. Brysocrypta Westwood, Int. Mod. Class. Ins., Synopsis, v. 2, p. 118. 
1847. Aphioides Rondani, Nuovi Annali Sci. Nat. Bologna (2), v. 8, p. 439. 
1857. Amycla Koch, Die Pflanz. Aphiden, p. 301. 
1857. Pachypappa Koch, Die Pflanz. Aphiden, p. 263. 
1857. Rhizomaria Hartig, Verhandl. d. Hils-Solling-Forstvereins, Jahrg. 1856, p. 52. 
1859. Tychea Koch, Die Pflanzenlaiise Aphiden, p. 296. 
1885. Kessleria Liechtenstein, Mon. Puceron du Peupl., p. 16. 
1904. Hamadry aphis Kirkaldy, The Entomologist, v. 37, p. 279. 
In 1837 Hartig erected his genus Pemphigus, although it was not 
until 1841 that his reference to the genus as generally cited appeared. 
Passerini in 1860 set bur 'sarins as type. In 1839 Haliday used the 
generic term Byrsocrypta but mentioned no species. In 1840 West- 
wood referred to this genus as Brysocrypta and gave hursaria L. 
as type. In 1859 Koch erected the genus Tychea with graminis 
Koch as type (mono typical). Schouteden (1906) has described the 
winged form. of Tychea graminis Koch and stated that it is a typical 
Byrsocrypta. The writer has had no opportunity to study specimens 
but on the strength of this statement of Schouteden places Tychea 
as a synonym of Pemphigus. It is worthy of note, however, that 
Schouteden did not mention the cornicles, and this is a point of 
considerable difference if graminis is a Pemphigus or if it belongs to 
the Fordini. 
In 1857 Hartig described the genus Rhizomaria with piceae Hartig 
as type. This species, however, appears to be a typical Pemphigus 
and Rhizomaria will become a synonym. 
In 1857 Koch erected the genus Amycla and of this genus j us cifrons 
Koch has been made the type. The writer has been unable to obtain 
specimens of this species but from the descriptions it seems almost 
