LEE BARKER WALTON 43 



E^. Capilliform sets longer than the diameter of the body. 

 Teeth of dorsal biuncinate setje remote . . N. oshortti. 



(N. America.) 

 C^. Prostomium slightly elongate, species large, approximately 



15 mm. in length N. luteum. 



(Europe.) 

 B^. Number of segments in an individual 40 to 61, no biuncinate 



setse in dorsal bundle N. dadayi. 



(S. America.) 

 A^. Prostomium developed into a short tentacular process, length of 



species approximating 8 mm N. breviseta. 



(East India.) 



NAIDIUM OSBORNI n. Sp. 



Prostomium moderately long, somewhat pointed. Eyes 

 absent. Digestive system differentiated into pharynx 

 (segments 1 to 3), esophagus (segments 4 to 7), and 

 stomach (8th segment). Dorsal bundle of set3e beginning 

 on the 2d segment, composed of 1 long capilliform 

 (145ja) and 1 short (50/x) seta, the latter biuncinate with 

 subequal, remote teeth and an indistinct nodulus one 

 third the distance from the tip. Ventral bundle com- 

 posed of 4 biuncinate setae with subequal teeth and a 

 distinct nodulus midway between base and tip. Length 

 1.6 mm. Number of segments in an individual 15 to 16. 

 Budding observed. 



Cedar Point, Sandusky, Ohio. 



Five species of Naidium have been described; three 

 from central Europe, one from the East Indies, and one 

 from South America; none, however, has been noted in 

 North America, consequently the occurrence of a distinct 

 species in the United States is of considerable interest. A 

 single individual was found in the sediment of a bottle 

 containing "reed roots" obtained at Cedar Point, Ohio, 

 and received from Professor Osborn, September 4, 1905. 



Schmidt (1847) founded the genus upon a single 

 species, N. luteum, occurring in Europe. Beddard ('95) 

 maintained that this species should be incorporated in the 

 genus Pristina inasmuch as Pristina breviseta described by 

 Bourne (1891) nearly bridged over the gap formerly sup- 

 posed to separate the two genera. Michaelsen (:00) 



