EEPOET ON THE ANNELIDA. 
485 
tint being deepest toward the tip, which distally is very short and slightly attenuate. 
So short is the naked apical region that in some it is difficult to distinguish. 
No trace of pigment-bar or spot occurs on the main radioles. The tentacle on the 
dorsal surface is very short, forming a pointed lanceolate process at the edge of 
each fan. A short secondary process, less free than the foregoing, occurs on each side 
externally. Both are connected with the first radiole or rib of the side. The inner or 
longer is shorter than the diameter of the body. On the ventral surface, again, where 
the tentacle is easily seen in Sahella pavonina, there is only a folded process, which 
bends downwards externally at the tip, and becomes attached to the web at the base of 
the three or four ventral radioles. 
The first bristle-bundle occurs dorsally as usual, immediately behind the collar, and 
has no hook-row. The anterior bristles, which throughout have a pale yellow colour, 
are arranged in two conspicuous groups in each tuft. Eight or ten elongate bristles, 
with more attenuate tips (PI. XXT Xa . fig. 16), form the dorsal series. Beneath is a 
much larger group, with tips so expanded that they are paddle-shaped, with a slender 
median prolongation (PI. XXTXa . fig. 17). The shafts of these, which are slightly 
constricted below the tips, are stouter than those of the foregoing. Both groups form 
a diminishing series, as regards lateral projection, from above downward. The posterior 
bristles are uniform in structure throughout, though two varieties are apparent, the one, 
however, passing insensibly into the other. Thus the anterior tufts of the posterior 
region present a somewhat alternate longer and shorter series, the longer having broader 
wings than the anterior dorsal, the shorter being longer and narrower than the anterior 
ventral. Towards the caudal region of the Annelid, again, both series have their tips 
greatly elongated (PI. XX TXa. fig. 18). 
The seven uncinigerous rows of the anterior region occupy prominent ridges situated 
between the bristle-tufts and the ventral scutes, only a short interval separating them 
from each of the foregoing. The last two are decidedly shorter. The hooks of these 
anterior rows have a somewhat pointed crown, with a series of fine serrations 
(PL XX I Xa . fig. 19). The breast or anterior curve is bold. The posterior process is 
rather long, and both it and the body below the crown are finely striated, the lines 
generally being continuous. The short bristles, with oar-like tips, accompanying 
the hooks, present no diagnostic feature. The posterior uncini have a longer neck, 
and the anterior curve is less prominent, but otherwise they correspond with the 
anterior. 
The tip of the body presents a somewhat prominent terminal anus, the folds of 
which exhibit a little reddish pigment. 
The fine muddy sand in the alimentary canal shows Diatoms, Radiolarians, and a 
few sponge-spicules, with hairs of minute Crustacea. 
The species inhabits a tube composed of closely aggregated and minute grains of 
