KEPOET ON THE ANNELIDA. 
367 
tened out in life on its grooved ventral surface, must have approached a circular or discoidal 
form, a peculiar feature in the group. The branchiae, again, are somewhat massive, clavate 
organs, also tinted of a pale madder-brown hue. Only a few project beyond the tentacles 
in the preparation. The anus is situated ventrally a little within the posterior border. 
The body has twenty -two bristle-tufts on each side, the ventral, in the case of all 
except the first, being stronger and much more conspicuous than the dorsal. 
In the first series the bristles are nearly of ecjual length, dorsally and ventrally, 
forming a beautiful long tapering pale golden tuft, which constitutes an elegant anterior 
fringe to the somewhat saccate body. The bristles of the ventral division of the 
first series arise from the prominent angles of the truncated anterior extremity, and 
their flattened shafts are ranged in a slight curve, with the convexity directed ventrally, 
and slanting from above downward and outward, while their slender tips form a fan- 
shaped fringe anteriorly. The first dorsal are represented by a series of broken stumps, 
situated a little behind the anterior margin of the body, on each side of the middle line, 
and running transversely outward beyond the upper series of the ventral bristles. They 
are pale golden bristles with a series of closely arranged transverse strise, which become 
further apart towards the tip, as usual in allied forms (PI. XXIIIa. fig. 11). They are 
also marked by fine longitudinal lines, and their tissue is somewhat brittle, the fractures, 
moreover, sometimes presenting a laminated appearance. While the transverse striae 
become considerably wider toward the tip (PI. XXIIIa. fig. 12), they again approach each 
other at the extremity of the bristle. The curvature of these long bristles is very 
evident towards the tip, and is indicated even in the minute portion represented in the 
last mentioned figure. 
The second bristle-tufts conform more closely to the type present throughout the rest 
of the body, presenting dorsally a series of long glistening golden bristles, which are only a 
little shorter than those of the first series, and aid the former in the construction of the 
frontal fan, while touching the ventral series by their under border. They agree in 
minute structure -with the first series, only they are somewhat less. In the ventral 
division, again, the bristles are proportionally shorter and thicker, with delicately tapered 
tips, and resembling that figured in PI. XXIIIa. fig. 13. 
The bristles of the third series are also longer than the others, both dorsally and 
ventrally, but nothing specially noteworthy exists in their structure. 
After the third the dorsal bristles become very slender and comparatively short, 
being scarcely distinguishable at first sight amongst the papillse of the lateral region. So 
• closely are they placed near the ventral bristles that they appear to be lateral or even 
ventral in position. They correspond in structure to the frontal, only being more slender 
and delicate. The striae are closely arranged at the base, widely separated toward the tip. 
The ventral bristles have a golden hue, are flattened, have a slightly curved shaft and 
a delicately tapered tip (PI. XXIIIa. fig. 13). With the exception of the latter, the 
