NKW AMKRICAN ACAKINA. 209 



SO.MK \RW ANKBCK'AM A<?AKIIVA. 



BY NATHAN BANK8. 



The mites of the United States I would arrange in eight .super- 

 families, viz. : Desmodecoidea, Psoroptoidea, Hydrachnoidea, Ixo- 

 doidea, Gamasoidea, Oribatoidea, Tromhidoidea and Eupodoidea. 

 In this article I shall treat of some forms belonging to the last two 

 super-families which I have observed in the United States, priiicipallv 

 from Long Island, N. Y. 



The study of mites is very difficult, and the classification is not 

 yet in a satisfactory condition. We have, except one or two small 

 papers, no works on Anjerican mites that are worthy of mention. 

 Quite a number of species have been described, here and there, bv 

 entomologists, who, by their descriptions and generic references, ex- 

 hibited their ignorance of the subject. The best European work for 

 classification, and within reach of all, is Canestrini's " Prospetto 

 dell'Acaro-fauna Italiana." Some valuable systematic papers have 

 also been published by Berlese, Kramer and Troussart. The super- 

 families may l)o roughly tabulated as below: 



1. — Body vermiforii), often with but roni- It'jis, living iu fjalls or in flesh, very 



minute forms DESMODECOIDEA. 



Not living iu frails or in fle.sli, adults with eight legs 2. 



2. — Water mites, soft bodied, mostly i>arasitic HYDRACHNOIDEA. 



Land mites 3. 



3. — No stigmata (atracheate) body soft, legs supported by chitiiious rods, no eyes, 



mostly parasitic forms ...PSOROPTOIDEA. 



Stigmata present (tracheate), no chitinous rods visible 4. 



4. — Last joint of i)alpus forming a tluunb or appendage, body soft, stigmata at 



base of mandibles, mostly free TROMBIDOIDEA. 



Last joint of palpus simple 5. 



5.— Stigmata above on the cephalothorax, each with a seta, body coriaceous, 

 cephalothora.x very distinct from abdomen, no eyes, none parasitic. 



ORIBATOIDEA. 



Stigmata not above, and without seta, body usually partly soft (i. 



6. — Mandibles forming a serrate proboscis, body hard, no sucker at ti[) of tarsus, 



eyes sometimes present, large, parasitic species IXODOIDEA. 



Mandibles not forming a serrate proboscis, smaller species 7. 



7. — Stigmata between legs two and three, often with hard plates, legs with a 



sucker at tip, no eyes GAMASOIDEA. 



Stigmata at base of mandibles, body wholly soft, no sucker at tip of legs, 

 eyes often present EUPODOIDEA. 



TRANS. AM. ENT. SOC. XXI. (27) JUNE. 1894. 



