| abstract | In this paper, a new species of the genus Haemogamasus Berl. is described and figured.
Haemogamasus quadratus, sp. nov.
Female (Figs. 1-7): Idiosoma oval, length 877µ, width 479µ. Dorsal plate covering almost the entire dorsum, 871µ long, 479µ wide, bearing numerous simple or weakly forked setae, those on the apical region being longer and stouter. The apical pair (F1) of setae and the pair at the posterior end of the dorsal plate still stouter and weakly plumose.
Sternal plate somewhat square in shape, 122.8µ long (at mid-line), 147.2µ wide (at the narrowest point); anterior margin concave at the middle; posterior margin slightly and irregularly incurved; lateral margins rather straight and nearly parallel to each other, lacking the usual antero- and postero-lateral projections on both sides. Of sternal setae, the first pair (St1) being shorter and plumose, the other two pairs (St2,St3) subequal and smooth. On the plate, 3 pairs of sternal pores present. Genitoventral plate weak1y expanded behind coxae IV; width 141µ, markedly broader than the distance between coxae IV. On the plate, about 40 nude setae present, of which 8 are slightly longer and arranged in pairs along the sides of the anterior 3/5 of the plate.
Anal plate pear-shaped, broadly rounded anteriorly, and narrow and pointed posteriorly, 122.2µ in length, 94µ in width, with 3 principal and 5 accessory setae. Adanal setae smooth, inserted at the middle level, of the anus; postanal seta weakly plumose, a little longer than the adanal setae; the 5 accessory setae being simple and short.
Gnathosomal setae, anterior pair smooth, others plumose. Chelae stout, with teeth; pilus dentilis narrow and pointed; the hyaline appendix at the base of fixed chela seta-like, with its tip reaching to 2/3 height of the chela. Tectum sub-triangular, with its apex rather obtuse; marginal fimbriae mostly simple, but some of them bifurcate.
Legs I, IV rather long and slender, but leg II rather short and stout. On the dorsal side of tarsus IV, 4 long plumose setae present, of which the marginal one being much longer.
Holotype ♀, collected off Rattus losea celsus G. Allen in February, 1957, from Yunnan Province, now deposited in the Institute of Zoology, Academia Sinica, Peking.
This species is similar to H. trapezoideus Teng et Pan, 1964, but differs from the latter by its somewhat square-shaped sternal plate, the lacking of accessory sternal setae, and the weakly plumose postanal seta. The dorsal plate and tectum are also different in form from those of H. trapezoideus. |