THE AMERICAN NA TURALIST. [Vol. XXXV 



Antarctica. It is to be remarked, however, that some of them may 



tropical Asia. Nevertheless, it is hard not to think Ripersiella, 

 Akermes, Ctenochiton etc. significant of some southern route. 



(4.) Holarctic Genera. 



Xylococcus, 3. 



Kermes, 28. On oaks. A species described from Australia 



Trionymus, 2. Exaeretopus, 2. 



Antonina, 7 (also China). Eriopeltis, 3. 



Eulecanium, 71 (one in Brazil). Physokermes, 3. 

 Lecanopsis, 3. Aclerda, 7 (and Natal, one species 



doubtfully congeneric). 



(5.) Nearctic Genera. 

 Olliffiella, 1 (making a gall on oak). Gymnococcus, 3. 

 Pseudophilippia, 1 (Florida). Philephedra, 1 (New Mexico). 



Toumeyella, 6. Comstockiella, 1 (on palms). 



Pseudodiaspis, 2 (one in Mexico). 



tropical, or evidently derived therefrom. Then; is no characteristic 

 Nearctic genus, generally distributed throughout that region, and 



(6.) Neotropical Genera. 

 Porococcus, 2 (Mexico). Dactylopius, 3 (one enter- 



ing Nearctic). 



Tectococcus, 1. Carpochloroides 1. 



