EEPOKT ON THE ANNELIDA. 
137 
setigeroiis region beyond the papilla is short and deep, having superiorly a conical process, 
beneath a rounded tubercle and a few crenations, and then a tolerably straight margin 
directed downward and inward. At the superior conical papilla a group of stout, pale 
yellow bristles emerge. The tip in each is dilated interiorly, marked by longitudinal 
stri£e, and is slightly concave on the ventral edge, which has a series of minute spines 
on an area near the base of the striae. . The bristles beneath are much more slender, and 
have the shape of elongated and delicate spears, the point of each being minutely hispid 
almost to the base of the dilated part.,) The bristles become more and more slender toward 
the ventral edge of the foot, and the spines on the tip are chiefly congregated along one 
edge, after the usual type of such bristles. The ventral cirrus is large and thick, and 
extends beyond the setigerous lobe of the foot. Its tip is tapered to a blunt point, with 
just a trace of an enlargement below. 
The second foot is similar, but it bears dorsally a comparatively stout cirrus. 
Superiorly a tuft of slender bristles with the attenuate spear-tips exists. The third foot 
carries the second scale, the fourth the third scale, the fifth a dorsal cirrus, the sixth 
bears the fourth scale, and so on alternately. At the tenth foot (bearing the sixth scale) 
a considerable alteration has occurred, a gradual change, indeed, taking place from the 
first backward. Below the scale the sides of the foot dorsally are covered with peculiar, 
elongated, and translucent papillse. The tip of the foot has in front a large vertical flap, 
which extends downward to about the middle of the foot ; this overlaps the tuft of long 
slender bristles superiorly, while the posterior margin of the extremity of the setigerous 
region is bordered by a similar though more adherent flap with which the stout bristles 
run parallel. In front of the latter, and extending beneath them, is a dense tuft of long 
slender bristles with hastate tips. 
The chief changes which ensue at the posterior end of the fragment are the increase 
in the number and size of the long translucent papillse on the dorsum of the foot, and 
the appearance of three large flat bullse of a similar nature on the ventral border. The 
ventral papilla at the posterior margin of the base of each foot forms a kind of pocket ; 
and the furrows at the bases of the feet dorsally cause the lateral regions to have a some- 
what symmetrically folded aspect. Other noteworthy changes are the great increase in 
the strength of the median vertical row of bristles, and the alteration in the type of the 
dense ventral tuft, each bristle in which presents a prominent series of spines on the 
dilated part of the tip, and flu ally merges into a long feathery terminal process. 
The foot (PL XXIII. fig. 8) at the posterior end of the fragment has superiorly a 
tuft of slender capillary bristles minutely serrated ; besides a dense group of silky hah’s, 
which form a felt-like mass after the manner of those in Aphrodita actdeata. They 
seem to end in simple filiform tips of extreme tenuity. A few of the somewhat slender 
forms with hastate tips then occur (PI. XIIIa. fig. 2), the elongate extremities being 
distinctly spinous, very much more so than in the anterior feet. The first and last 
(ZOOL. CHALL. EXP. PART XXXIV. — 1885.) LI 18 
