External features of regeneration in Clymenella torquata

Further Experiments on the Relation between Natural Fission and Regeneration in Stylaria fossularis

“…As regards the posterior regeneration in annelids, Hyman (1916) reported that the head of oligochaetes would not regenerate a tail unless a certain number of trunk segments were associated with it. In Clymenella torquata, Sayles (1932Sayles ( , 1934Sayles ( and 1936 found that the power of posterior regeneration , dropped progressively as the cutting was made at more and more anterior levels. All these references indicate the presence of gradations in the rate of posterior regeneration in annelids.…”

The morphology of the head, thorax, proboscis apparatus and pygidium of the maldanid polychaetes Clymenella torquata and Euclymene oerstedi

“…Some authors, describing Clymenella, (Leidy, 1855, as Clymene torquatus, Vemll, 1873, Lewis, 1897, as Axiothea torquata, Sayles, 1932, Ullman and Bookhout, 1949, Mangum, 1962 have numbered the first chaetiger as "2", in which case they have either assumed that the head contains only one unit of the metameric series, or they have used the word "segment" loosely to describe an externally recognizable portion of the body, irrespective of its constitution. Other authors have remained non-committal and have referred only to the number of chaetigers (Monro, 1937;Newell, 1949).…”

“…Behind these achaetous segments is a ring-shaped thickening which is a second cause of the discrepancies in the literature. Several authors count this ring (named the callus ring by Arwidsson, 191 1) as a 3rd achaetous segment (Verrill, 1873;Lewis, 1897;Sayles, 1932;Hartman, 1945;Wesenberg-Lund, 1948;Newell, 1949). Mangum (1962) describes Clymenella as having three achaetous segments, but says (personal communication) that she is not referring to the callus ring.…”