54 



shaped i^raiuilar papilla? occur in rows at the sides of the organ. 

 The brancliiic form a dense group of thread-like structures on 

 eacli side dorsally. Schmarda shows them of a bluish tint. 



The foregoing organs are enclosed by a fringe of golden 

 bristles, which with a dense series of elongated papilla? between 

 them form a web continuous at the sides, but with a gap 

 dorsally and ventrally. These bristles are comparatively short 

 in contrast with Troplioiiui, but their structure is similar, and 

 their curve is adapted to the contour of the wide fringe or pali- 

 sade which they form around the central organs. 



The long papilla? have slender stems with a fusiform dilata- 

 tion near the tip — which ends in a bulbous enlargement. 



The body is fusiform in outline, though by no means finely 

 tapered, indeed the ends are blunt. The skin is dark brown 

 and does not appear to have the abundant gelatinous tissue so 

 characteristic of Flabdligcm affiiiis. On each side of the dor- 

 sum is a series of bristle-tufts, the bristles having a similar 

 structure to those in front, and at each tuft is a dense group of 

 the long papilla?. The colour is dull greenish. 



Ventrally, again, each segment has two long and strongly 

 curved hooks (Plate iv. fig. 25) with slightly curved shafts 

 which have a dilatation below the sharp hook at the tip, and 

 another less marked at the commencement of the transverse 

 lines at the end of the shaft. The number of the lateral bristle- 

 tufts ranges from 41 to 54, Schmarda giving 37 body segments. 

 His specimens, however, were smaller. The surface of the 

 body has a considerable quantity of adherent sand-grains, 

 which are found both dorsally and ventrally, but they do not 

 form a continuous coat, much of the body being bare. The 

 rows of ventral hooks have a narrower space between 

 them than the dorsal bristles, the ventral surface of the tetrahedral 

 body being thus much less than the convex dorsal region. 



In regard to the sand-particles and their attachment it could 

 not be said that each was fixed to the tip of a papilla. The 

 grains seemed to adhere to mucus in which were sponge-spicules, 

 diatoms, and here and there groups of papilla?, but the latter 

 appeared to have no special connection with the particles 

 though they may have with the mucus. The sand-grains con- 

 tained manv calcareous fragments amongst the siliceous. 



The same sand with its coarser and finer particles occurred 

 in the alimentary canal. 



The general aspect of this form would seem to indicate that 

 it leans to Flabelligera, though no example had the membrane 

 between the hooks and bristles, and in this view it is satisfactory 

 to have the support of so able an investigator as Dr. E. Marenzel- 



