PALMER : COCCID GENUS PARLATORIA. 145 



and arrangement of the dorsal glands, the following classifica- 

 tion or key to the species has been worked out : 



A. — Dorsal glands absent or very minute and inconspicuous in the portion of the 

 pygidium cephalad of the first and second pairs of lobes. 



B. — Large dorsal gland with longitudinal pore cephalad of the third lobe, 

 the rudimentary fourth lobe replaced by a spindle-shaped thickening 



(see pi. XXVIII, fig. 2); lobes not notched or serrate cingala. 



BB. — No pronounced dorsal gland cephalad of the third lobe, the rudi- 

 mentary fourth lobe present ; lobes notched aonidiformis. 



AA. — Dorsal glands present and easily seen in well cleared specimens in the por- 

 tion of the pygidium cephalad of the first and second pairs of lobes. 

 B. — Median dorsal gland present. (PI. XXIII, fig. 1.) 



C. — Chitinous disks of marginal glands visible zizyphus. 



CC — Chitinous disks of marginal glands not visible hlanchardi. 



BB. — Median dorsal gland absent proteus. 



