45 (5) Mature worms up to 180 mm long, 4 mm diameter. Small 

 spermathecal pores located medial to (never in line with) the 

 lateralmost setae of the ventral bundles (Fig. 81). Dorsal 

 setae in posterior segments irregular, not in orderly ranks 

 (Fig. 82). No transverse genital marking on segment XIX 

 or XX Pontodrilus gracilis 



Figure 81 (top) . — Ventral view of segments VII to IX; A, B, lines 

 of ventral setae; B, lateralmost; L, seta; S, spermathecal 

 pores. 



Figure 82 (bottom). — Dorsal view of some posterior segments; 

 C, D, theoretical lines of dorsal setae; E, seta. 



— D 



-E 



ANNOTATED 

 SYSTEMATIC LIST 



The following check list of Oligochaeta is ar- 

 ranged systematically in families, with genera 

 arranged alphabetically under their family and 

 species under their genus. Notes on habitat, 

 ecology, life histories, and distribution in east- 

 ern North America are given where known. 

 References to im])ortant papers are cited under 

 families when applicable (monographs), and 

 individual species (systematics, ecology, and 

 distribution). References to species are cited 

 at the end of the annotation on each species. 



Class OLIGOCHAETA 



Family NAIDIDAE. Asexual reproduc- 

 tion, by means of fission, occurs commonly 

 in this family. References: Sperber 

 (1948), Brinkhurst and Jamieson (1971). 



Chaetogaster cristallimis Vejdovsky, 1883. Pen- 

 sylvania. Found in brackish water. Five 

 segments are formed anteriorly on fission. 

 (Brinkhurst, 1964.) 



Chaetogaster diaphanus (Gruithuisen, 1828). 

 Massachusetts to Georgia. Brackish water. 

 Predatory on smaller worms. Five seg- 

 ments formed anteriorly on fission. (Brink- 

 hurst, 1964.) 



Chaetogaster limnaei von Baer, 1827. New 

 England, but probably a cosmopolitan spe- 

 cies. Brackish water. Commensal on pul- 

 monate molluscs, living sometimes in the 

 kidney but usually in the mantle cavity; 

 feed on cercariae. (Brinkhurst, 1964.) 



Nais communis Piguet, 1906. Massachusetts to 

 Georgia (?). Brackish water. Five seg- 

 ments formed anteriorly on fission. ( Brink- 

 hurst, 1964.) 



Nais elinguis Miiller, 1773. Massachusetts to 

 Pennsylvania, but probably a cosmopolitan 

 species. Brackish water. Among floating 

 seaweed. Swims actively. Five segments 

 formed anteriorly on fission. (Brinkhurst, 

 1964; Lasserre, 1966.) 



Nais variabilis Piguet, 1906. Connecticut to 

 Georgia (?). Brackish water. Swims ac- 

 tively with spiral movements. Five seg- 

 ments formed anteriorly on fission. (Brink- 

 hurst, 1964.) 



Paranais litoralis (Miiller, 1784). Nova Scotia 

 to New Jersey. Brackish water and ma- 

 rine. Intertidal and subtidal to 7 m. In 

 sand, in sheltered localities. Four segments 

 formed anteriorly on fission. (Brinkhurst, 

 1964; Lasserre, 1966.) 



Stylaria lacnstris (Linnaeus, 1767). Pennsyl- 

 vania and New Jersey, but probably a cos- 

 mopolitan species. Brackish water. Prob- 

 ably among vegetation. Swims actively. 



18 



