582 Memoirs of the Indian Museum. [Vol. V, 



Garia, near Calcutta, burrowing in mud. 



The Cochin Backwater, near Ernakulam, in the Madras Presidency, September 

 1914. 



In the two former localities the salinity of the water is very variable, but never 

 high, probably never exceeding 1-015 at I5°C. The Cochin Backwater has also 

 water of very variable salinity, but precise information regarding it is not available. 

 It is part of a system connected both with the sea and with large freshwater lakes. 



Tylonereis fauveli, sp. nov. 

 (Plate XIX, figs. 3A-J, and text-figs, ^a-c.) 



Two complete specimens and fragments of four individuals of this species are 

 available for examination. 



The preserved specimens have retained very little pigment. The dorsum is pale 

 yellowish brown, and the head is faintly marked as shown in fig. 3A. The anal 

 segment (fig. 3B) is, however, of a conspicuously bright red colour. 



The body is slender, and rather more delicate and transparent than is usual in 

 the Nereidae. Of the two complete specimens, both of which are immature, one is 

 95 mm. long, composed of 200 segments, the other is 55 mm. long, with 150 fully 

 formed segments and a number of developing segments at the posterior end. Several 

 of the fragments apparently belong to larger specimens than either of these. 



The head (fig. 3A) is .rounded at the angles, divided into two lobes in front by 

 a shallow indentation. The width of the posterior part slightly exceeds the length. 

 The eyes are black, and the posterior pair are larger and closer together than the 

 anterior pair. All are provided with lenses. The tentacles and palps are normal. 

 The tentacular cirri are rather short, the anterior dorsal being two-thirds of the length 

 of the posterior dorsal cirri, and a little longer than the posterior ventral cirri. The 

 peristomial segment is only a little longer than the succeeding segments, and like 

 them is grooved in the lateral regions. 



The proboscis was not everted in any of the specimens, and its condition could 

 only be observed by dissection. No horny paragnaths are present, but two large 

 papillae were seen on the dorsal surface of the basal ring, that is to say, one in each 

 Group VI. An interrupted row of smaller papillae was seen on the ventral side of 

 the maxillary ring, in Group IV. None could be seen in Groups V, VII or VIII, but 

 they may be present, as it is difficult to observe the soft papillae in dissected speci- 

 mens. The jaws are small and slender, pale except at the tip, with 12 teeth. 



The feet increase in size up to the 6th pair. In the ist and 2nd feet the dorsal 

 setigerous division is absent. 



The ist foot (fig. 3c and text-fig. 3a) is relatively small. The dorsal cirrus is 

 a little longer than the dorsal ligule. The ventral setigerous lobe is somewhat 

 fusiform, and its base is enveloped on its anterior and ventral sides by a prominent 

 fillet, which in side view resembles an additional lobe, and gives a bifid appearance 

 to the setigerous lobe. In T. bogoyawlensky Fauvel represents the setigerous lobe as 

 terminating in three lobes (1911, PI. XIX, fig. 2). The setae are in three groups, 



