594 



Memoirs of the Indian Museum. 



[Vol. V, 





are still a little shorter and thicker. The ventral setigerous division consists of a 

 stout central papilla, pierced at the tip by a spine, and surrounded by a stout fillet, 

 which has an entire margin behind, but projects in front, forming a small lobe. The 

 upper group of setae consist of 3 spinous homogomphs behind, and 2 falcate hetero- 

 gomphs in front, the lower group of 7 falcate heterogomphs. 



The 2nd foot closely resembles the ist, except that the central papilla of the 

 setigerous lobe is rather larger. In the 3rd foot (fig. 7F, and text-fig. 6b) the dorsal 

 division appears. It consists of a small lobe, the rudiment of the dorsal ligule, and a 

 small fillet in front of the spine, and a single spinous homogomph seta. In the 

 ventral division the chief change is that the posterior margin of the fillet is produced 



Ointo a papilla similar to but 

 C J smaller than the one on the ante- 



rior margin. The setae are un- 

 changed. 



In the 10th foot (fig. 7G, and 

 text-fig. 6c) the normal condition 

 is shown. The dorsal and ven- 

 tral cirri are relatively much 

 smaller, whilst the upper and 

 median ligules are considerably 

 enlarged, especially the former. 

 The dorsal setigerous division con- 

 tains two spinous homogomphs, 

 the ventral division showing little 

 change in the setae. The dorsal 

 ligule gradually increases in size 

 from the 3rd to about the 23rd 

 foot, and attains a size equal to 

 that of the median ligule. 



The 30th foot is much the 

 same. The papillae on the fillet 

 of the ventral division are not so 

 prominent, and the margin is 

 more vertical. The dorsal ligule 

 has now begun to decrease again slightly. In the upper posterior part of the lower 

 ventral group of setae there is a single spinous heterogomph. In the 40th foot the 

 dorsal ligule is still smaller, and in the 50th foot is just shorter but thicker than the 

 dorsal cirrus. 



In the 60th foot (fig. 7H, and text-fig. 6d) the dorsal cirrus, dorsal and ventral 

 ligules are about equal in size, the ventral cirrus being smaller. The largest lobe is 

 the median ligule. The dorsal division contains three spinous homogomphs. The 

 ventral setigerous division is flattened from side to side, and the margins of the fillet 

 are rounded, the papillae noted in the anterior segments having disappeared. The 



CO 



Text-fig. 6. 



o 



-Parapodial diagrams of Nereis reducta, sp. 

 nov. 



a. ist foot. b. 3rd foot. c. 10th foot. d. 60th foot. 



■ = Homogomph setae with long tips ; x = Heterogomph setae with 

 falcate tip ; o = Heterogomph setae with long tips. 



