1914-] J- Stephenson : Oligochaeta from Northern India. 327 



In the present case the teeth of N . teauidentis, as described 

 by Walton, have a considerable resemblance to those of the 

 anterior, though widely different from those of the posterior, setae 

 of the present form.' 



The value of n, however, which is much smaller in the present 

 species, should serve easily to distinguish it. The smaller size of 

 the present form may also be mentioned, though of subsidiary 

 importance. 



Naidium minutum, sp. nov. 



Specimens of this worm were found in material taken from 

 the river Ravi near Lahore in February 1914. The animal is too 

 small to he seen except by hunting through the material with a 

 dissecting binocular over a black background ; with the exception, 

 perhaps, of Chaetogaster punjabensis, it is 

 the smallest Oligochaete known to me. 



The length of a chain of two animals, 

 moderately extended, is 2 mm. ; its breadth 

 in the extended condition o*i mm. Each 

 animal is a small whitish thread, often 

 marked, when seen by reflected light 

 against a black background, by spots or 

 transverse bands of a briUiant opaque 

 white ; these represent masses of coelomic 

 corpuscles. When the worm retracts the 

 anterior part of the body, the snout , from 

 the level of the first ventral setae for- 

 wards, is somewhat kinked upwards. 



The prostomium, with rounded end, is 

 longer than it is broad at its base ; it is 

 not elongated to form a proboscis. There 

 are no eyes. The number of complete 

 segments in a double animal is 17 or 19, 



excluding new segments just forming in Fig. 3. — Naidium miu- 

 the budding zone between the two; n= '^^^'"^^ dorsal needle-seta, 

 12, — constantly, so far as observed. The 



segments in the hinder part of the body, behind the stomach, 

 are much longer than those in front; the first six segments are all 

 quite short. 



The dorsal setae begin in segment ii, each bundle consisting 

 of one needle-seta and one hair-seta; the hair-seta is tapering, 

 and very slender, in length 8o~gOi^ (thus less than the diameter of 

 the body), and in thickness about i^*. The needle-seta (text-fig. 3) 

 is 35|U in length, and in thickness rather stouter than the hair, 

 something over i/^ ; its shaft has a shght double curve, and its 

 distal end is forked, the prongs being almost equal in length, 



^ The longer of the two prongs in Walton's specimens measured as much as 

 20m in length ; here the longer prong of the anterior setae is only 7 — 8/u, but the 

 animal itself is onl)- about half the size of Walton's form. 



