L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 6. 1991 (Budapest, 1991)

Martens, K.: On a small collection of non-marine ostracods from Mongolia, with the description of a new species (Crustacea, Ostracoda)

Furca (Fig. 1J) with claws subequal and slender, proximal seta inserted at about 2/5 of the total length of the ramus and relatively long. Furcal attachment short, stout and unbranched. Zenker's organ with the globular extremities typical of the genus and with ca. 14 spinous whorls. Hemipenis (Fig. 1D,E) with a complex labyrinth, a sclerified and globular part'd' and with inner spermiduct after the labyrinth showing at least 3 loops. Actual copulatory process a long stylus, straight and with sclerified walls, only slightly sinuous. Lateral shield (Is) strongly dilating, forming a nearly perfectly symmetrical triangle. Medial shield (ms) consisting of two lobes; ventral lobe subrectangular and relatively wide; dorsal lobe long and narrow, reaching about halfway the Is. Additional description of the female Valves (Fig. 1A) somewhat higher and more solidly built than in the male, but not longer. Surface ornamentation as in the male. A2 as in the male (see remark). Al, Md, Mxly Tl and furca either without special features or as in the male. Mx2 with palp 3-segmented, but with distal segment minute. T2 (Fig. 1L) with penultimate segment apically with 4-6 hook-like structures. Remark: the absence of a sexual dimorphism in the apical chaetotaxy of the A2 is a most interesting feature. The extent and nature of exactly this dimorphism has indeed been cited as a possible tool to create or at least falsify the higher taxonomy of the Cypridoidea (MARTENS 1987). It further illustrates that the Ilyocyprididae stand well apart from the Candoninae (which show an advanced sexual dimorphism in the apical chaetotaxy of the A2 - see DANIELOPOL 1978 and numerous other papers, BROODBAKKER & DANIELOPOL 1982), with which this group does share a number of morphological similarities. DIFFERENTIAL DIAGNOSIS 1. Based on classical features SARS (1903b) described Ifyocypris dentifera and 7. angulata from Central Asia. Both species differed mainly by the presence of lateral tubercules in the latter taxon, completely absent in I. dentifera. VICTOR & FERNANDO (1981) reexamined the types of both species and concluded that both nominal taxa were only the extremes of a series of intermediate morphologies of one and the same species. They suggested to consider I. angulata a junior synonym of /. dentifera. I here accept these views. Completely unaware of this paper, CHEN SHOUZHONG (1990) described the male of what he still called I. angulata. I. mongolica sp. n. differs from I. dentifera Sars by the undivided penultimate segment of the Tl in the latter species and by the shape of the ms of the hemipenis, which is a blunt, undivided lobe in /. dentifera. Other species of this genus cited from Central Asia are Ifyocypris bradyi Sars (as Ifyocyprella repens (Vavra) in DADAY 1904), which differs from the new species mainly in the length of the natatory setae on the A2 and Ifyocypris lacustris Kaufmann (in SARS 1903a), which has three lateral setae on the penultimate segment of the T2 (see below). At least the latter identification appears doubtful to me, and these specimens could belong to I. mongolica sp. n.