1899.] NATURAL SCIENCES OF PHILADELPHIA. 263 



cylindrical ; 1 very large. Segment 6 has two very long hairs at 

 the end. Interval between the antennae less than the greatest 

 diameter of the first segment. Candal tubercles little produced; 

 each with two bristles. Femora much swollen, legs otherwise 

 ordinary. 



Hah. — On date palms (Phcenix) imported from Algeria; found 

 by Mr. C. L. Marlatt, Avho made some study of it years ago. Mr, 

 Marlatt informs me that on the living plants the slight swellings 

 containing the insects are extremely inconspicuous, and very likely 

 to be overlooked even on close examination. 



Since the above description was written, P. marlaiti has been 

 found by the WTiter in great numbers on the insides of the sheath- 

 ing bases of the leaves of a date palm just imported from Algeria. 

 Here it is not beneath the epidermis. 



Dactylopiine Genera. 

 After a consideration of the larval characters, I am willing to 

 recognize five genera of Dactylopiini with the legs and antennje 

 rudimentary or absent. It is interesting that the larvae of these 

 forms, which are so degenerate in the adult stage, differ more than 

 do the larvae of ordinary coccids ; and, moreover, their differences 

 are just such as separate the adults of the genera which retain 

 their legs and antennae to the last. 



The following table will separate the genera mentioned : 

 Newly hatched larva elongate, after the manner of Rhizcecns and 



Pergandlella, antennae 6-segmented, 1 



Newly hatched larva oval or elliptical, 2 



1. Terminal antennal segment of larva oval, little longer than the 



one before Pseudolecanium Ckll, 



Terminal antennal segment of larva very large, as long as the 

 three before Ch.etococcus Maskell. 



2, Larva with 5 -segmented antennae; anal ring of adult with 4 



hairs Cryptococcus Dougl. 



Larva with 6-segmented antenna?; anal ring of adult with 6 



hairs Antonina Sign. 



Larva with 7 -segmented antennre; anal ring of adult and larva 



with 17 hairs Kermicus Newst. 



Sphcerococcus tohionu CkW.. , Bull. 4, Tech. Ser., Div. Ent., will 

 stand as Pseudolecanium tokionis. 



