A NEW GENUS AND SPECIES OF SUDAN LEECH FORMERLY CONFUSED WITH LIMNATIS NILOTIC A (HIRUDINIDAE S.L.: HIRUDINEA) By L. R. RICHARDSON SYNOPSIS A new genus is based on a leech from Zalingei Swamp, Sudan. It has 3 pairs of narrow broken lines on the dorsum, somitally repetitive supramarginal maculations, and a marginal light stripe; but there are 16 complete 5 -annulate somites, the posterior sucker is of moderate size, ejaculatory bulbs are present, and there are linear somital sense organs on the dorsal aspect of the posterior somites. A closely similar leech is recorded also from the Nile, near Fashoda. INTRODUCTION LEECHES with salivary gland papillae on the jaws have been found in all regions, essentially between 35 North and South. Of these, only leeches in the Mexican genus Limnobdella Blanchard 1893, the Australian genus Quantenobdella Richardson 1969, and the present leech have 16 complete 5-annulate somites, all others (Soos, 1969) have 15 such somites, including the leeches in the Ethiopian genus Limnatis Moquin-Tandon 1826 based on L. nilotica (Savigny 1822). The genus Limnobdella (v. Richardson, 1969 : 106, 'Potamobdella'} has a macrobdelloid pharynx with some muscular ridges ending independently between the jaws on the entrance to the pharynx, multiple small testes in each somite, the epididymis formed on both limbs of a simple primary loop on the anterior region of the male paired ducts, no ejacula-tory bulbs, the median regions bimyomeric and the female median region with an acaecate vagina and vaginal duct. The genus Quantenobdella described as lacking salivary gland papillae and having an hirudoid pharynx, is now found to have minute papillae and the pharynx smooth internally. Quantenobdella has simple saccular testes; the anterior region of the male paired duct lacks a loop and the epididymis is entirely posterior to the ejaculatory bulb, the two being linear in relationship; the median regions are bimyomeric and the female median region has a caecate vagina and a vaginal duct. In the present leech, the pharynx is hirudoid; the testes are simple, saccular; the anterior region of the male paired duct forms a simple primary loop with the epidi-dymis on the initial limb and an ejaculatory bulb on the terminal limb in a sub-parallel relationship; the median regions of the reproductive systems are as in Limnobdella. These differences warrant the provision of a separate and new genus for the leeches from the Sudan. It has been shown (Richardson, 1969) that the content of the former family Hirudinidae based on the genus Hirudo was unacceptably hetero-genous. Although separate families were provided then for Australian, Nearctic Bull. Br. Mus. nat. Hist. (Zool.) 21, 8
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