Scolecillus compositus Omodeo, 1958

Clausen, Martha Weis, 2004, Description of seven new species of Libyodrilus Beddard from Cameroon, with a key to the species of the genus (Oligochaeta: Eudrilidae), Journal of Natural History 38 (15), pp. 1851-1880 : 1877

Status of Scolecillus compositus Omodeo, 1958

Sims (1987: 379) provisionally assigned Scolecillus compositus Omodeo (1958: 91–93) to the genus Libyodrilus because of the presence of penial setae and intestinal gizzards. Scolecillus compositus should not be moved to Libyodrilus because it differs from Libyodrilus by characters of generic importance:

(1) The structure of the spermarium. In all species of Libyodrilus , the spermarium forms a ring around the oesophagus and there is a connection between the spermarium and the female organs. Neither of the two described species of Scolecillus has such a ring around the oesophagus and according to Omodeo (1958) there is no connection between the spermarium and the female organs.

(2) The position of the female pore. In Scolecillus this is in segment 14, in S. compositus in ab, whereas in all species of Libyodrilus it is in 15 (an unusual position in terricoles) and dorsal to d.

(3) The position of the gizzards. In some genera the position is not the same for all the species, but in Libyodrilus all the species have the gizzards in segments 23–25. In Scolecillus they are in 24–26.

It is not known whether the dorsal vessel in Scolecillus is doubled (but united at septal insertions) between 12, 13–21, 22 as in Libyodrilus as this information is not given in Omodeo’s (1958: 91–93) description of Scolecillus . In a later paper, Wasawo and Omodeo (1963) placed Scolecillus compositus in the genus Chuniodrilus Michaelsen, 1913 and not in Libyodrilus .