On some species of the oriental earthworm genus Pheretima Kinberg, 1867

Pheretima long has been known to have more species than any other oligochaete genus though no one has yet been in a position to determine how many of them have any real claim to recognition even as old-fashioned museum taxa. Intrageneric relationships are unknown primarily because somatic anatomy was derogated in the classical system of the Oligochaeta. Accordingly, if one wishes to learn whether any specimen at hand is of a known or undescribed taxon it is necessary, first of all, to check through appropriate portions of a 16-page table in Michaelsen's monograph (1900) where species are grouped according to location of the spermathecal pores. If identification is impossible, as often must be the case, a laborious search through the literature of the last sixty years is required. Pertinent contributions are scattered through numerous journals and books many of which seemingly have not been available to those who have been studying earthworms in various parts of the world. A similar knowledge of the literature is required even when identification is possible from Michaelsen's monograph as, for example, long synonymized names still are in use for common forms. Two keys have been published (Gates, 1937 and 1958) but they are regional and include only congeries of exotic forms introduced by man into India and the Americas. Clarification of some of the problems posed by one of the smaller groups, comprising forms with spermathecae opening at or near intersegmental furrow 5/6, now is possible because of assistance given by Dr. Y. Kondo, Dr. L. B. Holthuis and Dr. W. Vervoort, to whom the author's thanks are extended for making this contribution possible. MEGASCOLECIDAE