SYSTEMATIC TREATMENT 71 



Trionymus grindeliae n. sp. 

 Plate 3, fig. 26. 



In life. With a single pair of slender caudal tassels which attain 

 perhaps the length of the body. A root-infesting form. 



Morphological characteristics. Antennae 7-segmented in the adult 

 female. With but one pair of cerarii, these on the anal lobes and con- 

 taining two or three slender, conical spines, several smaller spines, or 

 spines and slender setae, and a cluster of numerous and rather scattered 

 pores. Dorsum with no multilocular pores. Dorsal body setae few, vary- 

 ing in size and shape from small and slender to quite large and stout, 

 those near the margin of the next to the last abdominal segment being as 

 large as the cerarian spines. Tubular ducts all very small, almost lacking 

 on the dorsum, but abundant on the venter. Anal ring setae somewhat 

 stouter and larger than the anal lobe setae. 



Immature specimens not observed. 



Type host and locality. From roots of Grindelia robusta on the cliff 

 at Pacific Grove, Monterey County, Calif., Dec. 1, 1917. 



Hosts and distribution. Known only as above. 



Notes: This species is extremely close to Trinoymus trifolii (Forbes), of 

 which I have had the privilege of examining a cotype specimen, received through 

 the kindness of Mr. Forbes, and other specimens from Missouri, received from 

 Mr. Hollinger. In fact these two are so very similar that it is only with much 

 hesitation that I conclude to regard my species as distinct. The only difference 

 of any importance lies in the fact that the dorsal body setae of T. trifolii are very 

 small and slender, while in T. grindeliae they tend to be much larger and stouter. 

 Further collecting may show the two to intergrade. 



This is not the place to discuss at length a species not coming definitely within 

 the limits prescribed for this paper, but I may note that the species Trionymus 

 trifolii (Forbes) has been consistently misunderstood. Another species, in all 

 probability Pseudococcus maritimus (Ehrh.), has been described as the "summer 

 form" of trifolii, and, so far as I can determine, all the published records since the 

 original description refer, at least in part, to this. 



Trionymus smithii (Essig). 

 Plate 3, fig. 27. 



1910. Ripersia smithii Essig, Pomona Col. Jn. Ent. 2:218-220. (In part.) 



1916. Pseudococcus smithii (Essig) ; Cockerell, Jn. Econ. Ent. 9:312. (In part.) 



In life. Concealed beneath the sheathing bases of the leaves of the 

 host. Slightly covered with secretion, without lateral or caudal tassels. 



Morphological characteristics. Antennae 7-segmented in adult fe- 

 male. But one pair of cerarii present, these on the anal lobes and con- 

 sisting of but two small conical spines not accompanied by grouped pores 



