POLY CH^ETA—BENHAM. 
75 
One of these had been cleared and mounted in balsam—it measures 4.7 mm., and 
consists of “ head ” and 26 chsetigerous segments. It had apparently been fixed in 
osmic acid, for many of the granules in the body wall and in the intenor of the body 
are blackened (fig. 82). 
The other, when it reached me in alcohoi, was flattened as if it had been studied 
under a cover slip : this I stained in alum carmine—its length is 3-5 mm. It is rather 
difficult to be sure of the number of chaetal bundles, for it is flattened asymmetrically, 
lying on one side with the ventral surface upwards, one series of parapods (of the left 
side) being along one edge for about half the length, the rest below the margin, the other 
series lying along the middle of the preparation—they are not easy to see except under a 
high power. 
I believe, however, that there are 25 or 26 pairs of parapods. The body is not other¬ 
wise segmented ; there are no external furrows, and internally there are several large ova 
which are without that regular arrangement they would have were any septa present. 
The ventral surface is fl at, the dorsal much arched. As the animal lies the distance 
from one set of parapods to that on the other side is about three times the width of the 
ventral surface. 
The whole surface of the animal is densely covered with crowded papillae (hence 
the specific nan e). These are well seen in profile along the edge, and each is a mass of 
cellular substance enclosed in a continuation of the cuticle of the body. Over the 
body the cuticle is unusually thick, but it becomes rather thinner as it rises up to form 
the wall of the papilla. Within are a few nuclei stained greenish-brown (in the osmic) 
and some pale carmine-stained protoplasm and threads. At the base the cuticle is 
pierced by a small aperture allowing a continuity between the contents and the substance 
of the body wall (fig. 87). 
The two ends of the animal are very similar : the anterior end does not present 
any differentiated prostomium ; no lobe is marked off from the first body segment. 
At a little distance from the end is a pair of eyes ; at least, so I interpret the structures. 
In the unstained cleared specimen there is a pair of sharplv-definecl oval vesicles 
surrounded by a firm membrane, pale brownish in colour, but without visible contents 
(fig. 83). In the stained specimen black pigment spots occupy a corresponding position. 
I cannot detect any tentacles, although 1 examined both specimens under high 
power. There are no processes, other than the papilla?, visible in these flattened 
specimens, and none of them are longer than their neighbours. The anterior end, like 
the rest of the body, is densely covered with these papillse. 
There is no distinct peristomium; the first bundle of bristles lies about midway 
between the eyes and the entrance to the pharynx, which must be a short distance 
behind the mouth, whose position I am unable to determine. The structure of the head 
is, in fact, just as Ehlers has described it for S. parvum, except that in that species 
he finds distinct tentacles, 
