SEXUAL PHASE IN INDIAN NAIDID^E. 



459 



usual in the genus. In sexually mature specimens, however, 

 they begin in segment viii. ; in one specimen there were needle 

 seta? only in the dorsal bundles of viii., but no hairs ; in a few 

 the setae only began in ix. ; in two cases the setae were seen to be 

 thrown off from segment viii. when a cover-glass was gently 

 placed over the worm, 



The body-cavity contains a large number of rounded corpuscles, 

 brownish in colour, and in addition there are a few colourless 

 corpuscles filled with refractile grannies. Ccelomic corpuscles 

 were more numerous in specimens which had been kept in the 

 laboratory for several days. They are few in the first six 

 segments. 



Text-figure 1. 



A. Veuicxl i^titsL oi JSla is jjectinata var. iuceqnalis. X 54.0. 

 13. Femal seta of BrancJiiodrilns Jiorte)i}iis. X 54.0. 

 Text-fig. 1 drawn by camera lucida. 



The pharynx occupies segments iii.-v., and is diffusely covered 

 by a small amount of chloragogen pigment, which extends right 

 up to the prostomium. In a transverse section the cavity has 

 the appearance of an inverted T, owing to the presence of a 

 median dorsal diverticulum ; this diverticulum and the dorsal 

 wall of the pharynx are ciliated. On the upper and lateral 

 surfaces of the pharynx are a number of pyriform cells, their 

 narrow ends resting on the surface of the pharynx ; these are 

 arranged in groups of three, four, or more, and the groups are 

 separated by strands of muscle which pass upwards from the 

 pharynx to the body- wall. The cells are about 30 in length 

 and 9 jj, in thickness ; they stain deeply with hsematoxylin. The 

 whole pharynx much resembles that of Ilcemonais Icmrentii (4). 



The gut is not distinctly differentiated into oesophagus, stomach, 

 and intestine ; it is somewhat larger in segments vi.-viii., then 

 narrow^ as far as xiv., after which it is continued as a fairly broad 

 tube for some distance. Its epithelium is ciliated. The anus is 



31* 



