202 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
easily break away. Farther back the setae in each ramus become very much stouter, not so long, have 
a brown color and smooth edges. Dorsal cirri appear first on third setigerous segment, at first rather 
short and cylindrical, increasing rapidly in length to about segment 16. A curious abnormality is the 
bifid or trifid end of many of these cirri on the specimen from station 139 ( fig. 57) . Branchia appear 
first in one specimen on sixteenth setigerous segment; in another on twelfth .setigerous segment; thev 
V? 
7 
l 
57. 
Figs. 54-57. — Aricia cirrata. Fig. 54, Head, x 12. Fig. 55, Anterior parapodium, x 23. Fig. 56, Posterior para- 
oodium, x 26; br., branchia. Fig. 57, Bifid dorsal cirrus from one specimen of A. cirrata , x 40. 
are small at first, gradually increasing in size up to the twelfth, which is full size; very prominent, 
fiat, with acute tips (fig. 56, br.). 
Color in places bright reddish brown; elsewhere, yellowish brown. 
Specimens incomplete. One of 75 segments; length, 50 mm.; width, 3 mm.; at narrowest 
point, 2.5 mm. Collected from stations 6061, 6066, and 6067. 
ARICIDEA Webster. 
Aricidea alata, n. sp. 
Head rounded, smooth; two very large, irregularly shaped eyes. Median tentacle straight, 
conical, reaching to anterior border of eye. First segment with parapodium. On the second the 
broad, flat, dorsal cirrus (“second gill”) becomes 
prominent, and from the third on these are very 
large, covering a large part of the back (fig. 58). 
They do not lie flat on the dorsal surface, but are 
elevated a little above it. Beginning with the 
second and ending with the thirty-first, the long, 
conical, dorsal gills arise from the dorsal edge just 
to the median edge of the dorsal cirrus. The latter 
spread out like broad wings on either side of the 
segment. In front of each is a row of stout, golden 
yellow setae (fig. 58). These are curved, tapering 
gradually to a sharp ap>ex, and marked by longi- 
tudinal striations (fig. 59). Ventral ramus with 
broad, flat posterior lip ( “ third gill ” ), with setae 
like dorsal. Toward posterior end both second 
and third gills become much less prominent, and 
the setae are fewer in number. Large hooked setae 
appear in the ventral ramus (fig. 60) . Throughout 
greater part of body a delicate longitudinal band of tissue runs along the side, uniting the parapodia 
of successive fragments. Color white. 
A single incomplete specimen of 54 segments. Length, 24 mm.; breadth, 1 mm.; from Arroyo. 
Figs. 58-60 .— Aricidea alata. Fig. 58, Anterior end, x 28. 
Fig. 59, Capillary seta from anterior segment, x 124. 
Fig. 60, Uncinate seta from posterior segment, x 143. 
