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. 



Characters. — Stem mother without cornicles but with wax plates; antennae five- 

 segmented. Alate form with cornicles; antennas 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-TT. 



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. Amy da, 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 Pflanzenlause Aphiden, p. 296. 



1885. Kessleria Lichtenstein, 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 lursarius 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 bursaria 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 Arnycla 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 



