284 J. H. ASH WORTH. 



nephridia, the two limbs of which are indicated iu some of 

 the anterior nephridia of his figure (pi. i, fig. 1) ; in these 

 nephridia the anterior limit is drawn broader than the pos- 

 terior, as is usually the case in large specimens. He appa- 

 rently overlooked the first two nephridia, which are small 

 and difl&cult to see, as they are partially hidden by the dia- 

 phragms. He describes the first nephridium as situated in 

 the sixth segment and immediately behind the last dia- 

 phragm. This is really the third nephridium, as may be seen 

 from a glance at fig. 14. The yellow granules observed by 

 Danielssen in the cells of the nephridia were probably excre- 

 tory. 



18. Eeproddctive Organs. 



Danielssen (1859, pp. 73 — 76) described Scalibregma as 

 hermaphrodite. He examined the tubular nephridia, and 

 concluded they were ovaries from which all the ova had 

 been discharged into the coelora. The parapodial glands 

 present on the dorsal and ventral cirri from the sixteenth to 

 within a few segments of the posterior end of the animal 

 were mistaken by him for testes, and the minute rods which 

 they contain were supposed to be spermatozoa. Scali- 

 bregma is not hermaphrodite, it is dioecious. As pointed 

 out above (p. 280), the paired segmental tubular organs are 

 nephridia, and the structures in the cirri are (p. 247) modified 

 epidermal glands which, instead of producing a liquid mucous 

 secretion, give rise to rod-like bodies which may be dis- 

 charged on the surface of the cirri. 



For a considerable time I was unable to locate the gonads, 

 as they are extremely small. The nephrostome is connected 

 to the body-wall by a thin sheet of tissue, which probably 

 represents the septum of the segment. On the surface of 

 this strand, and especially in the region of the smaller lip of 

 the funnel, there is a collection of loosely arranged cells pro- 

 duced by proliferation of the peritoneal cells covering the 

 base of the funnel and the neighbouring portion of the 



