106 PROC. ENT. SOC. WASH., VOL. 24, NO. 4, APR., 1922 



Type locality. Coachella Valley, California. 



Type slide. CM. No. 24720, U. S. N. M. 



Description based upon specimens on two slides, one of them 

 the type slide and the other a slide of cotypes. All specimens 

 collected July 22, 1921, in Coachella Valley, California, and sub- 

 mitted by A. D. 'Borden with the label "date mite." The 

 females of this species are similar to those of P. viridis (Banks) 

 but differ from viridis individuals in having the finger of palpal 

 thumb about one and two-thirds times as long as broad at the 

 base instead of being almost as broad as long as in viridis. In 

 the dimorphism of the male, as reflected in the tarsal claws, this 

 species differs apparently from all other species of the genus. 



Eupalopsis pavoniformis, new species. 



Species of Eupalopsis are characterized especially by having 

 the tarsal claws provided with pectines and by having the 

 abdomen divided by one or more transverse sutures. The 

 species here to be described is clothed with foliaceous and 

 plumose setae. At the caudal end of the abdomen is a whorl 

 of the latter, enormous in size. When this whorl is thrown for- 

 ward the plumose setae arrange themselves into a fan, like the 

 feathers of a peacock's tail when the peacock is strutting, hence 

 the name pavoniformis. As a common name for this mite that 

 of "The Peacock Spider Mite" is suggested. 



Female. Skin coarsely and somewhat irregularly reticulate; body clothed 

 with large foliaceous setae and at the tip of abdomen with enormous, finely 

 pectinate plumes; setae on legs foliaceous, pectinate setiform and simple seti- 

 form. Beak very long, slightly surpassing the palpi and deeply grooved above 

 for the reception of the chelicerae. Palpi rather large; claw large, stout and 

 strongly hooked; thumb slender, not swollen, tipped with two unequal setae, 

 and not quite reaching the tip of claw. Dorsally the cephalothorax bears six 

 foliaceous setae arranged into two longitudinal rows of three each. Abdomen 

 apparently two-segmented, the dividing suture passing entirely around the body 

 and just in front of the posterior coxae. Foliaceous setae on the dorsum of 

 abdomen arranged as follows: A transverse row of eight setae just behind 

 cephalothoracic groove; a similar transverse row, but of only six setae, just 

 behind the abdominal groove; a row of eight setae, the posterior one being much 

 reduced, along each lateral margin of abdomen; a circle of eight setae around 

 middle part of postabdomen and a single seta in the middle of circle. The tail 

 plumes are in a single whorl and number an even dozen. They are fully equal 

 in length to the total length of the body, are wavy and flagelliform toward their 

 tips, the flagelliform part of each seta being exceedingly minutely pectinate. 

 Legs short and stout; first pair longer than the others which are sub-equal. 

 Length, 0.44 mm.; width, 0.19 mm. 



Male. Unknown. 



