No. 2303. RED SPIDERS OF AMERICA— McGREGOR. 667 



PARATETRANYCHUS PERUVIANUS (McGregor). 



Tteranychus {Paratetranychus) peruvianus I^IcGregor, (peruianus) 1917, Proc U. 

 S, Nat. Mus., vol. 51, pp. 581, 582, 589, pis. 101-107. The name was mis- 

 spelled on p. 581, but properly spelled on p. 589. 



Color, translucent yeUo wish-green. Eyes (in mounted material) 

 clear, directly over front margin of coxae II. Dorsal bristles, 24 in 

 number, not arising from tubercles, for the most part very short and 

 weak, distributed on dorsal aspect of body in about the usual arrange- 

 ment. Body of female rhombic-ovate, widest across hind margm of 

 cephalothorax, which is shghtly emarginate in front; male cuneate- 

 pentagonal, widest across hind margin of cephalothorax, which is trun- 

 cate in front, abdomen tapering to acute point posteriori}^. Man- 

 dibular plate considerably more than twice as long as broad, margins 

 subparallel, v/ith a very distinct anterior emargination. ''Thumb" 

 of palpus very short in proportion to its vddth, bearing at its tip a 

 relatively large, subconical ''finger," whose base is half as wide as 

 tip of "thumb," length of "thumb" and terminal "finger" together 

 equaling width of " thumb." On its rather truncate tip, on opposite 

 sides of the "finger," are two stout spines or pseudo-fingers (not much 

 thicker than hairs) ; on upper side about one-third to base, is a small 

 "finger," and between this and base are two short hairs, the distal- 

 most one of which apj)ears to arise adjacent to the small "finger." 

 The davv^ on the penultimate joint reaches far beyond the middle of 

 the " thumb " ; a hair arises laterally from the center of the " thumb," 

 and another from a similar position on the penultimate joint. The 

 legs are unusually short, in the female distinctly less than the width 

 of the body, in the male barely exceeding the width of body. Femur 

 I considerably less than twice as long as wide, about half again as long 

 as tarsus I. Tibia I just equaling pateUa I, which barely equals 

 trochanter I. Tip of tarsus bears a stout, siclde-shaped claw, wliich 

 is unclef t to its tip ; arising from the under face of this claw, near its 

 base, are six weak spmes, which are less than one-fourth of the length 

 of the main claw. The usual series of four tenent hairs arise by the 

 sides of the base of the claw from the tip of the short onychium. The 

 egg is unknown to the writer. 



Type.— C&t. No. 20164, U.S.N.M. 



The type material was collected by Mr. E. W. Rust " along the line 

 of the Ferrocarril Central del Peru near La Legua (between lima and 

 Callao), Peru, South America, January, 1913, from the underside of 

 willow (Salix, species) leaves." 



