Observations on the morphology of some North American nemertines with consequent taxonomic changes and a reassessment of the architectonics of the phylum

Abstract

A majority of the nemertine species from the western North Atlantic were originally described from life in the nineteenth century. Many of these were established by A. E. Verrill who had 'an eye for species' no matter which phylum he was working with, and thus when living nemertines which he described are encountered, they can usually be recognized. The morphology of most of these species has never been reported; some may prove to be species described earlier from the eastern North Atlantic. Morphological observations on the nemertine species from the North East coast of the Pacific are inadequate and have prevented satisfactory comparison with species from Japan and eastern Russia. The morphology of some species collected in the Gulf of Maine and from Cape Cod, as well as a re-examination of some of the slides of type specimens of species from the west coast of North America, indicates that their generic placement must be re-examined. The architectonic plan of the heteronemertines postulated over 100 years ago can not be substantiated and is redescribed. Three new heteronemertean genera are described: Tenuilineus gen.n. Parvicirrus gen.n., Tarrhomyos gen.n. 157

A reassessment of the systematics and a proposal for the phylogeny of some cosmopolitan Lineus species (Nemertea)

“…Data from Riser (1993) are in agreement with our suggestion of keeping only one species designating all the fissiparous Lineus.…”

Molecular Phylogeny of Some European Heteronemertean (Nemertea) Species and the Monophyletic Status ofRiseriellus, Lineus,andMicrura

“…There have, however, been some attempts to reclassify the genus Lineus. Riser (1993) defined two new genera for species previously included in Lineus. Tenuilineus for Lineus bicolor, and Parvicirrus with Lineus dubius as type.…”

“…Tenuilineus for Lineus bicolor, and Parvicirrus with Lineus dubius as type. Riser (1993) concluded that Lineus socialis. L. sanguineus, L. nigricans, and L. vegetus all belonged to the same species (sanguineus by priority) and were separated from other Lineus species.…”

Ribbon worm relationships: a phylogeny of the phylum Nemertea

“…With the exception of Riserius pugetensis, all heteronemerteans in the study are classified in the family Lineidae. The type genus of this family, Lineus, is one of the four 'mega-genera', and some recent taxonomic revisions have been presented, mainly by Riser (1991Riser ( , 1993Riser ( , 1994, but have not found practical acceptance yet. In our analysis Lineus is, however, still non-monophyletic even with the application of Riser's new genera.…”