386 
PACIFIC SCIENCE, Vol. V, October, 1951 
Setigerous segments 2 to 8 are biramous. 
Each notopodium has seven to nine pointed 
setae and live to eight long-handled uncini 
arranged in transverse series. 
The abdomen consists of three setigerous 
segments followed by a short, tapering, 
slightly depressed pygidium, with a pair of 
dark eyespots located near the posterior end 
and lateral. The anal aperture is on the ventral 
side, a short distance in front of the eyes but 
median. It is followed by a short triangular 
lobe tapering distally. The proportions and 
locations of these parts are shown in Figure 2. 
Thoracic notosetae are of two kinds. The 
first three segments have fascicles of eight or 
nine each; these setae are long, slender, and 
distally pointed (Figs. 7, 8). Although they 
appear winged or bilimbate, the distal broad 
flange is thickened all around the stalk, as can 
be seen in cross section at the thickest or 
broadest part of the seta (Fig. 9). Similar 
setae are present in all other thoracic seg- 
ments. Beginning at the fourth one and con- 
tinuing in other thoracic segments, there are 
only five or six of the longer setae and the 
lower ones are replaced by three or four 
shorter, broader ones (Fig. 6). Thoracic un- 
cini are long handled and of a single kind 
(Fig. 3). They number 7 to 9 or 11 in single 
transverse series. Each uncinus is slightly 
beaked and has a large fang and several rows 
of smaller teeth (Fig. 4). 
Abdominal parapodia are biramous. Noto- 
podia are slightly elevated, transversely 
elongated, and have a single row of handled 
uncini that number 20 to 30 in a single series; 
the greatest number in a row is in the first 
segment and the least in the third segment. 
The largest uncini in a single series are at the 
inferior end of the row and there is a gradual 
diminution in size going upward. These 
uncini have a double row of seven or eight 
teeth in pectinate arrangement (Fig. 5). In 
normal position in parapodia, the tips of the 
teeth are directed outward and forward. In 
slide preparations the individual uncini are 
likely to have handles or teeth imperfect or 
broken. This fact, together with their small ! 
size (less than 20 micra for the length of the | 
distal part beyond the thickened shoulder), I 
doubtless accounts for imperfect or variable 
descriptions of abdominal uncini in the dif- ; 
ferent descriptions of species in the genus I 
Vahricia. \ 
Some of the specimens examined have 
many small spherical ova, crowded in thor- | 
acic setigerous segments 5 to 9. The only i 
color visible in living or preserved individuals I 
is limited to a few regions. There is a dusky | 
area on the ventral side of the collar and I 
ij 
peristomium; a similar pigment is on the dor- | 
sal side marking the notch of the collar; the 
prostomial cone and the palpi are dusky; the | 
eyespots in the peristomium and pygidium j 
are dark, and setae are pale yellow. I 
The tube is constructed of uniformly small, 
agglutinated sand granules ; it adheres closely 
to the occupant so that specimens fixed in 
the tube are difficult to remove. In life, re- 
moval can be effected by application of a 
drop of toxic fluid at the end of the tube. 
Holotype and other specimens are de- 
posited in the Allan Hancock Foundation of 
the University of Southern California, Los 
Angeles, California. 
DISTRIBUTION: Southern California, in es- 
tuarine marine mud flats. 
Fabricia dubia Wesenberg-Lund 
Fahricia sabella Berkeley, 1930, fig. Ig only. 
Fabricia dubia Wesenberg-Lund (1941: 33- 
35, figs. 2-4). 
COLLECTIONS: Many specimens come from 
South Bay in Coos Bay, Oregon, washed from 
intertidal rocks, August, 1950 (coll. Donald 
Reish) . I 
Individuals measure 2 to 3 mm. long and 
0.26 mm. across. There are eight thoracic and 
three abdominal setigerous segments; the 
last five thoracic segments are much the 
longest. The tentacular crown consists of 
three pairs of radioles, each having many 
paired filaments in bipectinate arrangement. 
The paired palpi are triangular and extend 
