276 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 99 



on heteromorphic males. Because of this difficulty the key to the 

 species is given for both sexes. It is hoped that in the future the sexes 

 can be correlated. 



Cheyletus hutleri Hughes and C. munroi Hughes, both males, were 

 described by A. M. Hughes in "The Mites Associated with Stored 

 Food Products," Ministry of Agriculture and Fisheries, London, 1948, 

 which was received after this paper was submitted for publication. 



KEY TO THE SPECIES OF CHEYLETUS 

 Females 



1. Dorsal setae pilose 2 



Dorsal setae smooth (?) parumsetosus Karpelles* 



2. Inner palpal comb with at least 8 teeth 3 



Inner palpal comb with 6 teeth promptus Qudemans* 



3. Femur of palpus distinctly longer than wide 4 



Femur of palpus about as long as wide 6 



4. Palpal claw with 3 distinct basal teeth 5 



Palpal claw with 2 simple basal teeth ; posterior dorsal shield with 3 pairs 



of setae eruditus (Schrank) 



5. Tarsus I sensory organ shorter than the guard seta hendersoni, new species 



Tarsus I sensory organ longer than the guard seta doddi, new species 



6. Anterior dorsal shield with 4 pairs of dorsal setae; posterior shield with at 



least 2 pairs 7 



Anterior dorsal shield with 6 pairs of dorsal setae; posterior shield with 1 

 pair strenuus Oudemans 



7. Shoulder setae simple, pilose 8 



Shoulder setae lanceolate ; posterior shield with 3 pairs of marginal setae. 



trouessarti Oudemans 



8. Claw of palpus with more than 1 tooth 9 



Claw of palpus with 1 tooth fortis Oudemans 



9. Palpal claw with 2 teeth 12 



Palpal claw with 3 or more teeth 10 



10. Palpal claw with 3 teeth 11 



Palpal claw with 4 teeth, the basal pair smaller than others. 



linsdalei, new species 



11. Posterior shield scarcely narrower than anterior shield ; dorsal palpal femoral 



seta pilose schneideri Oudemans 



Posterior shield considerably narrower than anterior ; dorsal palpal femoral 

 seta simple trux Rodendorf 



12. Posterior dorsal shield with less than 4 pairs of marginal setae 13 



Posterior dorsal shield with 4 pairs of marginal setae ; tarsus I guard seta 



pilose, about 4 times as long as sensory seta_ cacahuamilpensis, new species 



13. Posterior shield with 3 pairs of marginal setae 14 



Posterior shield with 2 pairs of marginal setae ; tarsus I guard seta pilose, 



about twice as long as sensory seta beauchampi, new species 



14. Tarsus I guard seta not longer than sensory seta 16 



Tarsus I guard seta about twice as long as sensory seta 15 



15. Sensory seta on tarsus I strongly lanceolate aversor Rodendorf 



Sensory seta on tarsus I slightly lanceolate davisi, new species 



♦ See p. 319. 



