RILEY NEW SUBTERRANEAN MITES. 215 



Descriptions of two new subterranean Mites. 



By Chas. V. Riley. 



[Fig. s.] 



^»_J|^ 





wr- ->?-- - 



Tyroglyphus phylloxer.e-u, b. dorsal and ventral views; c, enlarged jaw and 

 palpus; d, tarsus; e. anal tubercles of male; /, forms of tarsal projections; g, h, tarsal 

 terminations. 



Tyroglyphus phylloxera, Riley & Planchon, fig. 8.— When 

 full grown 0.03 inch long, and about half as broad. Colorpale yel- 

 lowish, with a brownish medio-dorsal circular spot, around which 

 there extends a gamboge-yellow discoloration, in some specimens 

 restricted, in others occupying nearly the whole upper surface of 

 the abdomen ; trophi, legs, especially two anterior pair, and 

 cephalothoracic sutures, of a faint rosy brown ; the epimera of a 

 deeper brown. The hairs of the body arranged much as in T. 

 siro. Linn, springing from minute papilla?, and not exceeding in 

 length A diameter of body. Tarsal or terminal joint of legs with 

 a short and prominent basal hair (d), sometimes fine and knob- 

 bed at tip. sometimes more fleshy and rounded at tip (/) ; often 

 lacking on the two hind pair ; also sometimes with other fleshy 

 growths (g) : tarsal claw usually distinct (d), but sometimes re- 

 tracted or obsolete {h). The usual pair of small tubercles each 

 side of vulva, and a larger flattened circular tubercle each side of 

 anal slit in <$ . 



When immature the color is whiter with less of the yellow, 

 dorsal discoloration, and the hairs are relatively longer. The 

 form varies according as the cephalothorax is retracted or not, 

 and the abdomen instead of being oval is sometimes constricted 

 in the middle, at others more spherical. 



