198 Memoirs of the Indian Museum. [Vol. VII, 



The spirit specimen is 3-5 mm. in length, and -23 mm. in thickness; it has 34 

 segments, with a short region posteriorly in which segments are not yet differenti- 

 ated. There is no budding zone. 



The prostominm is moderately large and long ; its length is equal to its breadth at 

 the base, and it is rounded anteriorly. There are no eyes. The anus is dorsal. 



The dorsal setal bundles begin in segment vi. They consist of one hair and 

 one needle seta, — never more than one of either. The hairs have approximately a 

 length equal to the diameter of the body. The needles are slightly sickle-shaped 

 (fig. 2), and forked distally; when the seta is in a good position for observation this 

 can be seen with the ordinary high power. The prongs are of the same length (the 

 outer may possibly be the least trifle longer), and join at an acute angle; the outer 

 seems to be slightly thinner. In length these needles are 52^, in thickness 2*5^. 



The ventral setae are of the usual type, and are usually 4 per bundle ; 3 and 5 

 were also met with. In length they are 52 m, in thickness 2 "5^. The inner prong- 

 is of equal length with the outer, but is twice as thick. I cannot see any difference 

 of type between the setae of segments ii — v and the rest ; but unfortunately the one 

 specimen is fixed in such a position that these setae can be seen well from neither 

 side, and the other (the already mounted specimen) seems to be the just separated 

 posterior animal of a chain, in which the anterior segments have not yet fully 

 developed. 



There is no stomach. Coelomic corpuscles are present. The cerebral ganglion 

 is bifid both anteriorly and posteriorly, and consists of two more or less independent 

 halves, contiguous for some distance along their inner borders. 



In the typical form of N. paraguayensis the outer prong of the dorsal needles is 

 considerably shorter than the inner, while in these specimens it is of equal length. As 

 however there appear to be no other essential differences, it will, I think, be sufficient 

 to describe them as a variety. 



Nais pectinata, Stephenson. 

 Gwalior, Central India; in a pond, attached to Hydrilla and other débris. 18-vi-1917. 

 B. Prashad. A single specimen. 



The specimen agrees generally with those previously described from Bheemanagar, 

 Travancore (6). Since the presence or absence of a stomachal dilatation is one of the 

 few internal marks that are used as specific characters in this genus, I may supple- 

 ment the original description by adding that there is none in this species. 



Nais gwaliorensis, sp. nov. 

 Plate IX, figs. 3, 4. 

 Gwalior, Central India ; in a pond, attached to Hydrilla and other débris. 18-vi-1917. 

 B. Prashad. A single specimen. 



The specimen is in length 27 mm., in thickness -25 mm. There are 29 segments 

 with a small zone behind where segments are not yet differentiated. There is no zone 

 of budding. The prostomium is bluntly triangular, its length being equal to its base. 

 Eyes are absent. There is also no stomachal dilatation on the alimentary canal. 



