LEE BARKER WALTON 39 



D^. Ventral bundle cemposed of 6 to 8 setx. Length 6 to 



8 mm. Color reddish N. josinoe. 



(Europe, N. America.) 



C-. Proximal tooth of dorsal biuncinate setje twice the length 



and twice the thickness of the distal tooth N. paraguayensis. 



(S. America.) 



A^. Seta: of ventral bundle of segments 8 to 10 much thicker than 



those of other segments, 1 to 2 in number, tips blunt, proximal 



tooth rudimentary N. brefscheri. 



(Europe.) 



NATS PARVULA n. sp. 



Prostomium blunt, rounded. Eyes present. Digestive 

 tract not differentiated into esophagus and stomach. 

 Dorsal bundle beginning on segment 6, composed of 1 

 capilliform, subequal to diameter of body, and 2 short 

 biuncinate setje. Ventral bundle consisting of 6 to 7 

 biuncinate setas with teeth equal. Length L2 mm. Num- 

 ber of segments in an individual 9 to 10. 



Cedar Point, Sandusky, Ohio. 



Several examples of this extremely small Nais were 

 found in the slime accumulating at the bottom of jars 

 containing roots of various aquatic plants obtained from 

 Sandusky Bay. It is chiefly remarkable by reason of its 

 small size, and the limited number of segments composing 

 the body. At first it seemed probable that it was an im- 

 mature form but evidence to the contrary was given by 

 budding in several specimens. 



NAIS TORTUOSA n. sp. 



Prostomium blunt, rounded. Eyes present slightly 

 dumbbell-shaped. Digestive tract not differentiated into 

 esophagus nor stomach. Dorsal bundle beginning on 6th 

 segment, composed of 1 long capilhform (180/a) and 2 

 short (50/x) needle-like set^e. Ventral bundle consisting 

 of 4 biuncinate setas (110/x) with subequal teeth. Length 

 2.2 mm. Number of segments in an individual 18. 



Cedar Point, Sandusky, Ohio. 



Two specimens belonging to this species were noted. 

 Budding was not observed. Several Peritrichous ciliates 

 {Khabdostyla sp., length 50/x, diameter \9ix) were ob- 



