io8 Records of the Indian Museum. [Vol. Ill, 



Sketches made during life by Capt. .Stewart confirm the above 

 identification, showing the animal to possess about the same pro- 

 portions as living specimens of the Lahore form. 



It will be noted that the individuals of the collections Nos. 42 

 and 49 are considerably smaller than those of No. 83. vSince, how- 

 ever, the size is the only point of difference I can discover, I have 

 not separated them as a distinct form. 



Since in distinguishing the species of the various families of 

 the Naididae so much depends on an exact description of the setae, 

 I will add here a somewhat more detailed account of those of this 

 species than I gave in my earlier paper. The setae are ventral 



only, slender, /- shaped, unequally forked, the distal prong being 



somewhat the longer, both prongs of the same diameter at the 

 base, nodulus small, somewhat, proximal to the middle of the 

 length of the seta ; setae of segment ii a little stouter and distinctly 

 longer ('14 mm., Lahore specimens) than the rest (average 'ii 

 mm., Lahore specimens). 



Nais sp. 



No. 42. Se-chen, Tibet ; 13,100 ft. ; 22-iv-07. 



A single specimen, without sexual organs, along with 

 specimens of Chcetogaster oriental is. 



Length 2 mm. ; segments xviii plus a short posterior region 

 without setae, the seat of budding of new segments. Prostomium 



rounded. Ventral setae with a j -shaped curve, hooked and bifid 



distally, distal prong longer than proximal ; nodulus not distin- 

 guishable in the present specimen ; beginning in segment ii ; 2 — 3 

 (perhaps more originally) in bundle. The anterior and posterior 

 bundles differ somewhat ; the anterior are composed of setae about 

 •074 mm. in length, with the distal prong of the forked end of the 

 same thickness as the proximal ; in the rest of the body the ven- 

 tral setae are about '055 mm. long, or three-quarters the length 

 of those of the first few bundles, and the proximal prong is very 

 considerably stouter than the distal. The thickness of the shaft of 

 the seta is, however, the same throughout the body. 



Unfortunately a small quantity of foreign matter adheres to 

 the ventral surface of parts of the animal, and the setae in these 

 places being obscured, I am unable to say how many segments are 

 comprised in the anterior group ; probably', however, as in A^ 

 oblusa, the setae of segments ii — v belong to the anterior, the rest to 

 the posterior group. 



The dorsal setae begin in segment vi ; each bundle appears to 

 consist normally of one long smooth hair-seta, and one short, 

 straight, singly-pointed needle-seta supporting it at its base, and 

 scarcely projecting bej'-ond the surface. These dorsal bundles, 

 however, have been much damaged. 



