622 



Memoirs of the Indian Museum. 



[Voi,. V, 



covered by a thin, soft, sticky layer, transparent in itself but soon powdered with 

 fine silt, which adheres to it firmly. This soft external layer and also the outer, stiff er 

 layer of the central mass are continued at the base to form a narrow tube, which is 

 usually filled with the excreta of the worm. The tube goes straight down into the 

 mud for a foot or more and is inhabited by the parent worm. In the photograph 

 of an egg-mass of M. gravely i here reproduced the basal tube is well shown ; also the 

 thin external layer, which is torn at one place, revealing the egg-mass with the minute 

 contained eggs or larvae. 



Dr. Gravely adds that the unhatched larvae (text-fig. 13 l b) can move freely in the 

 jelly in which they are embedded. They closely resemble^ Borradaile's larvae, but 



minute examination revealed somewhat great- 

 er differentiation among the cilia than is 

 indicated in his figures. Two groups of 

 setae crushed out of a larva with two seti- 

 gerous segments are shown in text-fig. 13* . 

 It will be observed that of the simple setae 

 in the anterior group one is pointed at the end 

 and the other somewhat blunter, as described 

 by Borradaile. There is, moreover, a single 

 jointed seta associated with them.. Neither 

 this jointed seta nor the one in the second 

 group is, however, quite like either of the 

 jointed setae figured from Borradaile's older 

 larva. The figures of the Chilka larva have 

 been prepared under Dr. Gravely' s supervision. 



A minute nematode worm Monhystera uria, Stewart [Rec. Ind. Mus. X, p. 247) 

 is found in the jelly with the larvae. 



Habitat. — 27 specimens of this species were taken at 7 stations in Chilka Lake. 

 All the stations were in the southern end of the lake, from Nalbano to Rambha, and 

 the bottom was muddy. The species was apparently only taken during the salt- 

 water season, from January to March. In this part of the lake, however, the specific 

 gravity is only from 1/008 to i'on.5 in the salt-water season. It is certain that the 

 species lives in this area throughout the year, when the gravity is as low as i'ooi, and 

 is only obtained in January to March because, at that time, the level of the water has 

 sunk so low that the mud flats and banks, in which the worm lives, can be examined. 



Text -fig. 13*. — Parapodium of larva of Mar- 

 physa gravelyi, sp. nov., highly magnified. 



Lumbriconereis polydesma, sp. nov. 



(Plate XXVI, figs. 15A-1,, and text-figs. i/\a-c.) 



Only one specimen, fortunately quite complete, and a fragment of a second of 

 this species were taken in the south-western end of Chilka Lake. It is 185 mm. in 

 length, and is composed of 386 segments. It is not fully grown, as genital products 

 are absent, and new segments are in process of formation in front of the anal segment. 



