AQUATIC EARTHWORMS 639 



10 (11) Setae of dorsal bundles all uncinate. . Paratmis Czerniavsky 1880. 

 P. litoralis (Muller) reported as abundant on the New England coast and may occur in adja- 

 cent fresh waters. The first dorsal setae are on V. 



11 (10) Dorsal setae nearly straight, slightly toothed or simple-pointed. 



Ophidomiis Gervai.s 1.H38. 



B«an^(ii<f.^!i'!JBrl"llL_Mi ^" ^^>'P^"^^'^'^ (Miiller) may be easily rccoKnizcd by the 



^^^1^^^^"^' ■W^^ Htefcr K. small irregularly distributed dorsal sctar; by the four larKC 



^P^^^I''l^^o''^o-^^^^^^ transverse pigmented areas on the anterior resion, and 



-li^To- '■ ''Wl ! *? '' °o J^ by the relatively large size. Length 25-30 mm. 



'^j ^ ''^- ,>;>.U^^>-W^.,^ sjf Fig. 983. AnterioT tndolOphidonais serpentina. X 40. (After 



""""T '' ^ Piguet.) 



12 (9) CapiUiform setae present in dorsal bundles 13 



13(21) First anterior dorsal setae on V or VI 14 



14 (18) Posterior end not modified into a gill-bearing respirator}- organ; 



first anterior dorsal setae on \'1 15 



15 (16, 17) One or more capilliform setae of VI much longer than those of 



other somites and equal to three or four times the diameter 

 of the body Slavimi Vejdovsky 1883. 



S. appendiculata (d'Udekem), common in some parts of the United States, has Ixidy surface 

 studded with sensory papillae and with foreign bodies. 



16 (15, 17) Prostomium elongated to form a proboscis; dorsal setae of \'I similar 



in length to those of other somites. Stylaria Lamarck 1816. 



S. lacustris (Linnaeus) has proboscis flanked by promi- 

 nent lateral prostomial lobes (Figs. 980 and 9!^4);. -*>• foi- 

 sidaris Leidy lacks the lateral prostomial lobes (Fig. 984). 

 The former' is abundant and widely distributed in the 

 United States while the latter is reported only very infre- 

 quently. 



Fig. 984. 



Prostomium and proboscis, Stylaria. A, S. laeuitrii 



B.S./ossularis. X40. (Original) 



17 (iK, 16) Without proboscis; dorsal setae of VI similar in length to those of 



other somites A'd/^ Muller 1774. 



Several species without conspicuous differences are reported from the United States. A'. 

 elinguis Muller is one of the best-known species and A^. communts I>.guet is very common. 



18 (14) Posterior end modified into a gill-bearing respiratory organ, the 



branchial area ^^ 



10 (20) Ventral margin of the branchial area with a pair of long processj-s. 

 ^^ ^ .l;</()/)//t;r//5 Schmarda iSoi. 



A Jurcatiis (Okcn) has the first dorsal setae on V and 

 has two pairs of well-develo,R'd gills 



A vagus Leidv crawls or tloats about m a tube made 

 ; ^i;:'^^-. from bryozoan statoblasts and bits .)f vegetation It hw 



the first dorsal setae on VI and has only slightly devel- 

 oped gills. 



Fig q8s. Posterior end of .1 ulo Chorus /urcaius. 

 ^ Bousflicld.) 



X 40. (After 



