A new species of Phthiracarus (Acari, Cryptostigmata) from Austria B. W. Parry Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction A small collection of mites from oak litter in the Vienna Woods, Austria was examined by Sheals in connection with a computer study of phenetic affinity within the Phthiracaroidea (Sheals, 1969). The material was found to contain several specimens of an undescribed phthira-carid mite, the notogastral integument of which was particularly striking and apparently unique amongst the known members of the superfamily. Moreover, although the species showed an overall similarity to Steganacarus, its anal chaetotactic pattern corresponded to that of Phthira-carus. Classification of the mite was deferred at this time and Sheals excluded it from his study. However, in view of its interesting morphological features a detailed description was considered desirable and is given below, based on the seven available specimens. Family PHTHIRACARIDAE Perty, 1841 Phthiracarus papillosus sp. nov. Aspis (Figs 2-4; PI. Ib): 242-282 urn long and with a greatest width of 181-212 urn. All the dorsal setae are rather long, stout and procumbent. The interlamellar setae (//) are about 1-5 times the length of the lamellars (la) and extend two-thirds of the distance between the bases of the interlamellar and rostral setae (ro). The latter almost reach the anterior aspal margin. The sensilli are 40-55 um long, lanceolate and striated. Three finger-like tracheoles are associated with each bothridium and there is a single pair of short exobothridial setae (ex). In front of the il-la setae there is a pronounced median keel and on each side three lateral keels arranged in an oblique row (PI. Ib). Of the lateral keels, the paraxial pair is the longest and the antiaxial pair the shortest. The prodorsal integument is not strongly ornamented and appears to be finely punctate as in other Phthiracarus species. Behind the sensilli the integument is raised into a number of low longitudinal ridges. Notogaster (Figs 1, 5; Pis la; 2d): 464-606 um in length along a line through c^-h^ and with a greatest depth of 333-484 urn. All the setae are stout, slightly recurved and more or less equal to the distance c^-d^ (PI. la). Seta c 3 is inserted on the posterior margin of the collar and setae (Va submarginally. Vestigial f v is located just below the seta h v . The fissures ip and ips are present. In one paratype ip and ips were only present on one side. The integument is densely and irregularly papillate (PI. 2d). Ano-genital region (Fig. 9; PI. If): There are two pairs of comparatively long anal setae (an^) located marginally and three pairs of adanals (ad^) forming an oblique row submarginally, the longest in the row being ad 2 which is approximately equal in length to the anal setae. Scanning electron micrographs show that all the setae on the anal plates are weakly serrated. On each genital plate there are nine simple genital setae arranged in two rows. Setae g!_ 5 are minute and located on the paraxial border while the other four pairs (g 6 _ 9 ) are moderately short and submarginal. A single aggenital seta ag is located antiaxially in the genital furrow. The integu-ment of the genital and anal plates is weakly papillate (PI. If) with the exception of the areas bearing setae (an^*,) where the integument has no distinct ornamentation. There are three pairs of genital papillae, the anterior pair being rather small. Bull. Br. Mus. not. Hist. (Zool.) 37 (1) : 73-79 Issued 29 November 1979 73
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