666 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



Type. — Paratetranychus ununguis Jacobi, designated by Tra- 

 gardh, 1915. 



KKV TO THE SPKCIES OF GENUS PARATETRANYCHUS. 



1. Appendiculate spurs at base of tarsal claw about one-quarter the length of the main 



dorsal claw division; femur I about lialf again as long as tarsus I ; palpal "thumb" 

 over twice as wide as long; terminal "finger" about half again as long as thick; 



mandibular plate deeply emarginate P. peruvianus McGregor. 



Appendiculate spurs at base of tarsal claw half or more the length of the main dor- 

 sal claw division 2 



2. Main dorsal division of empodial claw decidedly exceeding the basal, appendicu- 



late spurs; palpal "thumb " of male longer than wide 3 



Main dorsal division of empodial claw not conspicuously exceeding the basal 

 appendiculate spurs; palpal "thumb " wider than long 4 



3. Terminal "finger" of palpal "thumb " well developed, at base fully half as wide as 



tip of "thumb"; tarsal appendiculate spurs rather closely appressed and fused 

 toward the bases; penis shaft stout, bent sharply to form acuminate hook; 

 mandibular plate elongate, truncate or broadly rounded in front without emargi- 



nation P. pralensis Banks. 



Terminal "finger" of palpal "thumb'" of male inconspicuous, much less than half 

 width of "thumb " at tip; tarsal appendiculate spurs widely radiate, free to their 

 bases; penis shaft slender, together with acuminate hook forming sickle-shaped 

 structure; mandibular plate wide, broadly rounded anteriorly without emargi- 

 nation P. ununguis Jacobi. 



4. Terminal "finger" of palpus three times as long as thick, not oA'^er twice as thick as 



lateral "finger"; ventral tarsal claw division cleft barely more than half its 

 length, and the six appendiculate spurs rather closely clustered; mandibular 



plate not plainly emarginate P. modestus Banks. 



Terminal "finger" of palpus not much longer than thick, from three to five times 

 as thick as lateral "finger"; ventral tarsal claw division cleft nearly or quite to 

 base, and considerably divergent; mandibular plate more often emarginate 5 



5. Mandibular plate not emarginate 6 



Mandibular plate distinctly or indistinctly emarginate 7 



6. Terminal "finger" of palpal "thumb" spatulate in outline; lateral "finger" short, 



tack-like; main dorsal claw of tarsus with greatest thickness at mid-point. 



P. pilosus Canestrini and Fanzago. 



Terminal "finger" of palpal "thumb" subconic in outline; lateral "finger" long, 



banana-shaped ; main dorsal claw of tarsus thickest at base P. viridis ' Banks. 



7. Dorsal bristles arising from prominent tubercles 8 



Dorsal bristles not arising from prominent tubercles 9 



8. Tarsus equaling femur; mandibular plate almost imperceptibly emarginate; hook 



of penis longer than shaft, bent 60° from main axis of penis; tarsal claw with six 

 appendiculate spurs; subfrontal bristles about three times as long as frontals. 



P. citri McGregor. 



Femur from one-quarter to one-fifth longer than tarsus; mandibular plate distinctly 



emarginate; hook of penis about half length of shaft, bent over 90° from main 



axis of penis; tarsal claw with five appendiculate spurs; subfrontal bristles only 



one-quarter again as long as frontals P. ilicis McGregor. 



9. Femur about t^\'o and one-half times as long as wide and one-quarter again as long 



as tarsus; tarsal claw with six appendiculate spurs P. bicolor Banks. 



Femur about half again as long as wide and hardly equaling the tarsus; tarsal claw 

 with five appendiculate spurs P. yothersi McGregor. 



» VirldU and simplex are synonyms; the former was the earlier and holds. 



