PROC. ENT. SOC. WASH., VOL. 24, NO. 4, APR., 1922 105 



species, which is the second gall-making spider mite to be re- 

 ported, has many morphological and biological affinities with the 

 true gall mites, the Eriophyidae, and throws much light on the 

 origin of the latter degenerate and highly specialized group. 

 This gall-making species will be made the subject of a paper to 

 be presented later on the phylogeny of the Eriophyids. 



The first mentioned species belongs to the genus Para- 

 tetranychus Zacher, which genus is characterized by having one 

 simple and one strongly deflexed divided tarsal claw. 



The divided claw is split into 5 or 6 spurs, the inner one or 

 two of which are usually somewhat stouter than the others. 

 A formal description of the new species follows. 



Paratetranychus heteronychus, new species. 



Female. Distinctly larger and stouter than the male. Mandibular plate 

 about three-fifths as broad as long and evenly rounded in front. Palpi moder- 

 ate; thumb slightly exceeding claw, terminal digit about one and two-thirds 

 times as long as broad at its base and pointed distally, two terminal digituli 

 situated just above digit and each slightly surpassing the latter, sense seta fusi- 

 form, equal to digit in length; claw of palpus rather slender and strongly hooked 

 toward tip; antepenultimate segment of palpus ring-like, about three times as 

 broad as long. Abdomen with rather long simple setae arranged in the usual 

 manner. Legs moderate, the anterior and posterior pairs being about equal anil 

 longer than the second and third pairs. Tarsal armature as follows: four 

 tenent hairs in two groups as usual, outer hair shortest, inner next in length and 

 two middle hairs longest and subequal; a single simple claw slightly over one- 

 half as long as middle tenent hairs and a deflexed split claw of the six usual 

 prongs the inner, or most strongly deflexed, ones being slightly stouter than the 

 others. The deflexed claw is about two-thirds as long as the simple one, its 

 inner spurs very slightly surpassing the somewhat tubercle-like base of claws. 

 The simple claw is more strongly curved toward its tip and is rather slender 

 throughout its length. Length, 0.38 mm.; width, 0.20 mm. 



Male. Smaller and more slender than the female, especially in the abdominal 

 region. Palpal spur conspicuous, slightly recurved and situated on a prominent 

 internally and dorsally situated tubercle. When the palpus is viewed from 

 the inside this spur-bearing tubercle is seen to extend forward and upward for 

 over half the length of the antepenultimate segment; antepenultimate segment 

 longer, relatively in the male than in the female. Penis of the telarius type; 

 inner lobe slightly longer than the shaft; basilar lobe apparently absent; shaft 

 broad and stout, being fully one-half as broad at its base as it is long; hook 

 short, recurved beyond 90 and with flattened barb. Legs relatively more 

 slender than in the female; tarsi of first pair with two simple claws! One of 

 these claws slightly shorter and deflexed. It evidently represents the barbed 

 claw of the female. The deflexed daw of the second pair of legs is not simple 

 yet differs from the corresponding claw of the female in that it is split into 

 barbs for only a part of its length. Length of male, 0.31 mm.; width, 0.15 mm. 



