Redescription of Bolbella californica — Jones 
end, corresponding body diameter 44/a; tail with 
a single subterminal seta, with caudal gland 
orifice, length 187/x. 
INTRASFECIFIC VARIATION: A limited num- 
ber of measurements were made on 62 of the 
79 available specimens of B. calif ornica. Based 
on these measurements mean ratios and corre- 
sponding ranges of body length/body width 
( = a ) , body length/ esophagus length ( = b ). , 
body length/tail length ( = c), and vulva posi- 
tion as percent of body length ( = Vu) were 
calculated. A summary of these results appears 
in Table 2. 
A variation exists in the number of bulbi in 
the esophagus of females. Either 9 or 10 are 
present, but some specimens with 10 bulbi 
possess an indistinct anterior bulbus. Each of 
the two males examined has 9 bulbi. Allgen 
describes B. californica as possessing 7 to 9 
esophageal bulbi; his figure (figure 50) shows 
8. It is probable that he failed to note the in- 
distinct anterior bulbi. 
All other species of Bolbella possess 8 bulbi 
(Inglis, 1961) or less (7 in B. heptabulb'a Timm, 
1961 ). 
ECOLOGICAL NOTES 
The offshore area of southern California is a 
complex assemblage ' of islands, banks, ridges, 
basins, and troughs designated as a "continental 
borderland” by Shepard and Emery (1941). 
The narrow strip of bottom immediately adja- 
cent to the continent forms only 6.2% of the 
continental borderland and is designated the 
mainland shelf (Emery, I960). 
Samples were collected along the inner margin 
of the shelf from off Santa Barbara to off San 
Diego, California, in 2.4 to 10.1 m. B. californica 
163 
occurred at 18 of 100 sampling locations. The 
mean depth of water was 7.6 m (range, 5.5 to 
9.1) at these 18 locations. This agrees closely 
with the depth given by Allgen (1951:368), 
3.6 to 9.1 m, for the type locality in San Diego 
Bay. 
Bottom sediment at the type locality is de- 
scribed as "sandy” (Allgen, 1951:368). In the 
present study, sediments where B. californica 
were collected are variable, as the following 
values indicate: % gravel, 0.0 to 29.0 (mean, 
1.7); % sand, 40.6 to 93.8 (mean, 67.1); % 
silt-clay, 2.7 to 59.4 (mean, 31.1). Median 
diameters have a somewhat more limited range 
of 56 to 163 /a (mean, 78/a), in part due to the 
lack of clays in all but one sample. All sediments 
were well sorted, 1.15 to 1.41 (mean, 1.25). 
Major elements of the macrobenthos asso- 
ciated with B. californica are summarized in 
Table 3. The most important of these are the 
polychaetes Nephtys caecoides and Prionospio 
malmgreni; the amphipod Paraphoxus epitomus; 
the cumacean Diastylopsis tenuis; and the mol- 
lusks Teilina buttoni and Olivella baetica. 
METHODS 
The nearshore portion of the shelf, in water 
depths from 2.4 to 10.1 m, was sampled from 
the motor launch of the research vessel "Velero 
IV,” using a modified 1/10 sq m Van Veen 
grab. The methods utilized in the shipboard 
handling and the laboratory analysis of these 
samples are described by Hartman, Barnard, and 
Jones (I960). The animals collected were lim- 
ited by the size of the mesh, 0.495 mm, through 
which the sediment was screened aboard ship 
before preservation and sorting. 
TABLE 2 
Intraspecific Variation in Length Measurements 
$ $ (52) RANGE (MEAN) 
$ $ (2) RANGE (MEAN) 
JUV. (8) RANGE (MEAN) 
L* = 2.29 
— 3.35 
(2.78) 
2.20 
— 2.72 
(2.46) 
1.98 
— 2.44 
(2.20) 
a = 25.4 
— 43.3 
(33.2) 
26.9 
— 31.6 
(29.3) 
33.0 
— 47.8 
(39.5) 
b = 3.1 
— 4.6 
(4.0) 
4.1 
— 4.3 
(4.2) 
3.5 
— 4.3 
(4.0) 
c = 11.7 
— 20.4 
(16.8) 
14.8 
— 16.0 
(15.4) 
14.4 
— 19.6 
(15.8) 
Vu = 38.3 
— 47.2 
(43.2) 
* Abbreviations: L = length in millimeters, a = body length/body width, b = body length/esophagus length, c = body 
length/tail length, Vu = vulva position as percent of body length. 
