NO. 2167. SEVEN NEW SPECIES OF RED SPIDERS— MCGREGOR. 585 



about continuous with the inner lobe, but bends shghtly downward, 

 then extending backward as a straight, slender spur, terminating in a 

 very sharp point. 



Type.— Cut. No. 20165, U.S.N.M. 



The type material is from the south slope of Mount Hood, Oregon, 

 above Government Camp, at an altitude of 6,000 feet, August 23, 

 1915, from underside of leaves of large-berried huckleberry (Vac- 

 cinium, species). Considerable discoloration and dropping of leaves 

 accompanies the mite's activities. The species is rather close to T. 

 oregonensis, described herein, but is readily distinguished from the 

 latter through the marked differences in the form of the penis and 

 collar trachea. As far as we know this estabhshes a record for alti- 

 tude for a red spider species. 



TETRANYCHUS OREGONENSIS, new species. 



Color, straw-color or pale yellowish amber; lateral spots lacking 

 or very inconspicous. Eyes pale, a single one on either side near 

 base of subfrontal bristles. Legs and palpi paler than body. Dorsal 

 bristles, 26, in four rows, plumose, pale, longest bristle (subfrontal) 

 equal to half the breadth of body. Body elhp tic-ovate, 0.304 nun. 

 long by 0.142 mm. wide; vertical thickness of body greatly reduced. 

 "Thumb" of palpus very short, nearly half again as wide as long, 

 bearing at its tip a fairly ample "finger," whose base, however, is 

 shghtly more than one-third the width of "thumb" at tip. On its 

 upper distal corner are two pseudo-fingers; on upper side hardly 

 midway to base is a very small "finger" or sensiUa, and between 

 this and base are two short hairs; a hair arises latero-ventrally from 

 the center of the "thumb." The claw on the penultimate joint 

 reaches to the dorsal "finger." The spur on the second joint of the 

 male palpus is rather long and tack-like. The legs are rather short, 

 about three-fourths the length of body. Femur hardly twice as 

 long as wide, equaling the tarsus; tibia one-fourth longer than patella, 

 which barely surpasses the trochanter in length. Relative length of 

 joints as follows: Trochanter, 10; femiu*, 21; patella, 11; tibia, 14; 

 tarsus, 21. Tip of tarsus bears a claw, which is strongly bent below 

 its middle; the portion beyond this point is cleft into six nearly 

 straight claw divisions, the two inner of which are somewhat stronger 

 than the others. The usual series of four capitate hairs arise by the 

 sides of the claw base. Collar trachea of novel type; runs backward 

 and downward as a straight even-cahbred tube, and then bends 

 sharply upward into a short wide chamber, the two arms making an 

 angle with one another of less than 90°. In the one rather poor male 

 specimen the penis shaft appears to taper gradually to a strong, 

 unbarbed hook. 



Type.— Cat. No. 20166, U.S.N.M. 



