ARKIV FÖK ZOOLOGI. BAND 6. N:o 2. Speleorcliestes, a new genus of salttatorial Trombidiidae, whicli lires in termites' and ants' nests. By IVAR TRÄGÅRDH. D. Se; F. E. L. With 14 Textfigures. Communicated Mai 12th bv Chr. Aurivillius and Y. Sjöstedt. While amongst insects the power of jumping or leaping is by no means uncommon, there are, up to the present time, known only two genera of saltatorial mites. Of these one, Zetorchestes Berl. belongs to the Oribatidae the other Na7i-orchestes Tps. & Trt. to the Trombidiidae. The latter genus, of which only one species is known, was found in France, in crevices of the rocks on the shore, within the limits of the tide. It is closely related to the present genus and indeed at first I referred the two species on which it is founded to Nanorchestes. But on closer exa-mination of the somewhat meagre diagnosis, which is not accompanied by any figures, I found recorded details enough to enable me to say that they cannot be referred to Nan-orchestes. The two species, on which the present genus is founded, were discovered, one, S. tennitophilus, in a partly deserted termites' nest in Zululand at Entendweni Bush in June 1905, the other, 8. formicoru^n, in the nest of Formica rufa, not far from the shore. at Arilds läge in Skåne Sweden in June 1907. Arkiv för zoologi. Band 6. N:o 2. 1