594 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



its length from either end the anterior border is excavated for the 

 attachment of a tentacle. These are shorter than the head, rather 

 thick, and taper rapidly to a sharp point. Two other tentacles are 

 attached to the ventral surface of the head and are not visible from 

 above. These are similar to the dorsal tentacles in form, but are 

 heavier. One pair of small eyes lies near the anterior border. Just 

 posterior to the right hand one of these is a dark spot which re- 

 sembles an eye, but is, I think, merely a surface marking. Two 

 tentacular cirri on either side are attached to the first somite. They 

 are much like the tentacles in form, but about twice as large. The 

 mouth is bounded anteriorly by the prostomium, while about one- 

 third of the posterior border is made up of an anterior prolongation 

 from somite 2. 



The first parapodium is about two-thirds as long as the second, but 

 is similar to it in all other respects. 



A well-developed parapodium (fig. 2 — an anterior view of the 

 fifteenth) shows the setigerous portion prolonged into bifid presetal 

 lip, behind which arises a row of about 25 compound setae with 

 elongated basal joints. The notocirrus is broadly rounded and car- 

 ried on a large cirrophore. The neurocirrus is bluntly conical in 

 outline, with its dorsal surface next the setigerous lobe rather deeply 

 excavated. 



The compound seta (fig. 3) has the basal portion very slightly 

 curved, the convex side apparently with a narrow transparent edge, 

 which thickens abruptly at the apex. The apex has a sharp hook 

 at the end of the convex surface, with a much heavier curved hook 

 opposite it. This larger hook lies a little inside the line of the con- 

 cave margin, which is continued into a much smaller spine. Ap- 

 parently other smaller spines of uncertain arrangement are located 

 around the base of the large hook. The terminal portion is broad 

 at the base and tapers to a sharp point, the whole terminal portion 

 being about as long as the free part of the basal portion. Near its 



base there are minute denticulations along its thinner edge. I was 



'. . . • 



unable to determine the extent of these denticulations, but think 



that they do not go beyond the middle of the joint. With careful 



focussing, fine lines, giving it a shagreen appearance, may be seen on 



the surface of this terminal joint. 



A later parapodium (fig. 4) shows a cirrophore larger than the 

 cirrus, and there is a black spot in the center of the cirrus. In the 

 preparation the whole cirrus was bent away from the observer so 

 that the cirrus was really larger than appears in the figure. The 

 setae in these parapodia are similar to those farther forward. 



Collected a£ station D5146, Sulade Island, vicinity of Siasi, 24 

 fathoms, coral sand and shell bottom. 



Type.— Cat. No. 18940. U.S.N.M. 



