REFORT ON THE NEMERTEA. 31 



the larger and give off the stout nerve-cords. The cords stretching backwards on either 

 side unite with one another above the rectum at the hinder end of the body. The nerve- 

 ganglia are shown enlarged in fig. 3 ( = fig. 30). No sense-organs of any kind were detected. 

 On the outer margin of the large superior ganglion (fig. 3) a series of elongate pellucid 

 cells were arranged side hj side perpendicularly to the curved surface which they form. 

 Abundant fine nerves were given off' from the entire length of the nerve-cords to the 

 surface of the body, the muscles, &c., arising both from the inner and outer margins of 

 the cords. At the origins of these nerves from the cords there are very slight swellings 

 on the margin of the cord, but these do not contain any nerve-cells. The nerves are very 

 fine, hyaline, with a nearly rectilinear course, and they generally divide into two near 

 their points of distribution ; they are never tortuous or much ramified. Terminal organs 

 on the surface of the body in connection with the nerves were carefully sought for but 

 could not be found. 



" A pair of vascular trunks follow the course of the nerve-cords through the body, lying 

 internally to them and beneath them. The vessels unite with one another posteriorly, as 

 do the nerve-cords ; their course is undulating. J,ust behind the nerve-ganglia the 

 vascular trunks are enlarged into wide reservoirs. No branches of these vessels were 

 seen, and though the animal was living when examined, no pulsation in them was 

 observed. The vessels had a pellucid wall, in which were imbedded elongate oval nuclei 

 (fig. 4, & = fig. 28), but which otherwise appeared structureless. No motion of any fluid 

 within the vessels was seen. 



" Although the specimen under description was evidently so immature, well-developed 

 ovaries were present, the specimen being a female, as was the adult one before obtained. 

 The ovaries follow in their disposition the vascular trunks so closely as to appear as if 

 connected with them. The ovaries are simple ovoid sacs with a distinct wall (fig. 2 = fig. 31), 

 filled with ova (in various stages of development) and granular matter. A dark irregular 

 fissure appeared on the centre of each ovary as viewed from the dorsal surface, which I 

 believe to be an opening by which the cavity of the organ communicates with the exterior, 

 thus dorsally. The ovaries were not quite regular in disposition, an extra anterior one 

 being developed on the right side of the body. In the interspace between the most 

 anterior and larger pair of intestinal diverticula and- the next posterior pair were four pairs 

 of ovaries, whereas in the succeeding corresponding interspaces were only single pairs of 

 these organs. In the adult specimen described in the 'Annals' (March 1875) a single 

 ovarian sac only was present in each interspace between the diverticula of the digestive 

 tract. It would therefore seem probable that on further development three pairs of 

 diverticula would have budded out between the first and second pairs in the present 

 specimen. 



" The muscular system consists of a series of excessively fine transversely or circularly 

 disposed fibres, which are external in position to a series of broad band-like longitudinal 



