Kansas IInivehsity Science Bulletin. 



Vol. Ill, No. 5. OCTOBER, 1905. 1^0^x111'™!: 



ON THE DORSAL GLANDS AS CHARACTERS OF CON- 

 STANT SPECIFIC VALUE IN THE COCCID 

 GENUS PARLATORIA. 



BY MIRIAM A. PALMER. 

 With plates XXIII to XXVIII. 



T^HERE has been much confusion as to classification of the 

 -■- different species of the genus Parlatoria. About nineteen 

 species have been described, but the status of so many of these 

 has been so uncertain that authorities have differed among one 

 another, even the same authority being found to cliange hi? 

 opinion from time to time. 



Cockerell (1896, c, and 1899,6) and Mrs. Fernald (1903) 

 give the genus as consisting of seventeen species, but do not 

 agree exactly in their lists of species, and Marlatt, in his manu- 

 script of March, 1900, tentatively declares the genus to consist 

 of at most but six species. The cause of this confusion is the 

 v^ant of established constant specific characters on which to 

 base a system of classification. 



It is the purpose of this paper to give the result of investiga- 

 tions made upon the pygidia of the females of a number of the 

 species of this genus for the purpose of ascertaining constant 

 specific characters. The species or so-called species studied 

 are aonidiformis Green, hlanchardi Targ,, cingala Green, mytil- 

 (ispiformis Green, proteus Curt., pergandei Comst., crotonis Ckll., 

 thei^e Ckll., and variety euonymi Ckll., victrix CkW . , viridis Full., 

 thefe viridis Ckll., and zizyj^hus Lucas, these being all that have 

 been available. All the literature at hand on these species has 

 been carefully consulted and compared in making conclusions. 



For studying the characters herein discussed great care must 



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