The study of new samples of oligochaetes from Lake Baikal (Siberia) made possible description of two new species of thegenus Rhynchelmis, R. alyonae sp. n. and R. shamanensis sp. n. Rhynchelmis alyonae sp. n. has modified genital setae, a charactermentioned for the third time in the Lumbriculidae. These species belong to a complex of small Rhynchelmis, characterisedby two pairs of testes, two pairs functional sperm funnels, no connection between spermathecae and gut cavity, and short,elongate, straight atria extending, at most, into segment XII. Other representatives of this group are R. olchonensis, R. paraolchonensisand probably R. spermatochaeta. The Hrabe specimens of R. olchonensis are not considered to belong to this speciesand are included into R. shamanensis sp. n. An examination of the ultrastructure of spermatozoa of R. alyonae sp. n. indirectlygives some support to the validity of this group. The group is suspected to harbour other new species in Lake Baikal where itseems more and more to constitute a species flock.