8 A CONTRIBUTION TO THE KNOWLEDGE OF 



Notes: As far as may be judged from the literature available to me for 

 examination it remains to be demonstrated that any of the American species now 

 referred to this genus are congeneric with the type. In none of the descriptions 

 of the type species that I have seen is any mention made of the presence of the 

 marsupium or of the opening of the marsupium (erroneously described hereto- 

 fore as the vaginal opening) which is the salient character of the genus as rep- 

 resented by the three species, P. townsendi (Ckll.), P. plucheae (Ckll.) and P. 

 morrilli Ckll. Should it prove that these three are indeed not congeneric with P. 

 fuscipennis (Burm.), the genus Crypticerya, with P. rosae (Riley & Howard) as 

 type, might be revived for them. 



In all respects this genus is very close to Icerya, the only significant differ- 

 ence being found in the presence of the marsupium. In the immature stages the 

 marsupium is not developed and specimens are not at all distinguishable from 

 specimens of Icerya of corresponding age. The ring of pores which forms the 

 margin of the opening of the marsupium is apparently homologous with the ring 

 of pores by which the ovisac is formed in Icerya and the marsupium itself is 

 homologous with the area included within this ring of pores. 



Paleococcus morrilli Ckll. 

 Fig. 2. 



Type host and locality. From undetermined host, Jerome, Ariz. 

 In material of this species received from Professor Cockerell there re- 

 mained a fragment of the host plant which agrees in all respects with 

 Acacia greggii. The probability that this is the host is increased by the 

 fact that the species has been taken from Acacia greggii on two other 

 occasions. 



Material examined. Specimens from the type material and from 

 Acacia greggii, near Vail, Ariz., and at Cottonwood, Ariz., the latter col- 

 lected by E. Bethel and received by the author from Professor Cockerell. 



Habit. A large species, about 7 mm. long, 4.5 mm. high and 5 mm. 

 broad, high convex and somewhat pyriform, the posterior portion broad- 

 est; dark gray in color (becoming red when dried), slightly dusted over 

 with white secretion and with longitudinal rows of short, white tufts of 

 secretion. 



Morphological characteristics. Adult female with the dorsum spar- 

 ingly beset with small spines and setae which become longer and more nu- 

 merous on the head. Margins with a series of large, stout setae, arranged 

 singly, each accompanied by two or three short, stout spines. On the 

 abdomen these groups of setae and spines are arranged segmentally. 

 Depression containing the anal opening surrounded by many slender 

 setae. Derm with relatively few pores, these all small and of one size 

 and type and tending at intervals to form clusters which coincide with 

 the tufts of secretion. Ventral side of the abdomen with numerous short 



