Revision of the eastern African earthworm Polytoreutus (Eudrilidae : Oligochaeta) R. W. Department of Zoology, British Museum (Natural History), London SW7 5BD Contents Introduction ... Variation .... Taxonomy Genus Polytoreutus Key to adults of the species kenyaensis species group . meruanus species group magilensis species group . kirimaensis species group . kilindinensis species group coeruleus species group arningi species group . Acknowledgements . References 253 254 258 259 262 264 269 274 279 283 287 294 297 297 Synopsis Fifty-three nominal species and subspecies of the genus Polytoreutus are revised; descriptions and a key are provided to seven species groups here recognized and 27 species now regarded as valid (five being new to science). Introduction The earthworm genus Polytoreutus was described by Michaelsen in 1 890 to accommodate a highly variable eudriline species, coeruleus, from Tanzania. Its distinguishing characters are: a single male pore, a single spermathedal pore in furrow 18/19, the absence of penial setae and a single pair of testes in segment xi. During the first five years following its description, another seven species were recognized on other characters (Beddard, 1895) and altogether eleven species and six subspecies were known by the end of the century (Michaelsen, 1900); at the time that Stephenson published his monograph (1930), the genus contained 32 species compared with the 53 nominal taxa from central and eastern Africa examined during the studies reported below. During the ninety years or so that have elapsed since the description of Polytoreutus, the included taxa have not been reviewed nor have intraspecific and other variations been recorded with the result that several species have been described as new more than once. This present report contains the first revisions of the nominal taxa assigned to the genus, seven species groups are recognized containing 27 species now regarded as valid (five being described as new). The current revision became essential in order to identify material of the genus Polytoreutus among the collections of earthworms made in eastern Africa by Miss Edna Oxtoby. In 1964 Miss Oxtoby was appointed to the staff of Kenyatta College, Nairobi and resumed teaching biology after fifteen years as an Education Officer (later Senior Education Bull. Br. Mus. not. Hist. (Zool.)43 (5): 253-298 Issued 25 November 1982
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