384 
PACIFIC SCIENCE, Vol. XXI, July 1967 
TABLE 2 
General Seasonal Variations in Surface Temperature and Thermocline Depth 
and Intensity in the Outer Santa Barbara Passage 
MONTH 
SURFACE T°C 
DEPTH OF 
THERMOCLINE 
MIDPOINT 
T°C CHANGE IN 
TOP 40 METERS 
January 
14.00 
absent 
less than 1 
February 
13.80 
absent 
less than 1 
March 
14.50 
20 m 
3.0 
April 
14.00 
15 m 
3.0 
May 
17.50 
25 m 
4.5 
June 
18.00 
20 m 
5.0 
July 
19.00 
no data 
no data 
August 
21.00 
18 m 
8.3 
September 
21.10 
27 m 
5.1 
October 
20.10 
25 m 
4.0 
November 
16.85 
25 m 
5.3 
December 
15.00 
absent 
1.3 
ing the day. The factors influencing this type 
of deep-water migration are not clear. The ab- 
sence of perceivable light and the relative con- 
stancy of temperatures exclude these factors 
as being important at such great depths. The 
vertical movement of Rhachotropis natator may, 
in fact, represent an endogenous rhythm and 
thus be independent of the environmental con- 
ditions. 
Family lysianassidae 
Eurythenes obesus (Chevreux) 
Katius obesus Chevreux, 1905: 1-5, figs. 
1-3; Stephensen, 1925: 126-127; Schellenberg, 
1926: 217-218, fig. 2 6d; Barnard, K. H., 
1932: 56-58, fig. 21, pi. 1, fig. 1; Chevreux, 
1935: 63-65, pi. 10, figs. 4-6, pi. 11, fig. 10. 
TABLE 3 
Day and Night Depth Distributions for 
Rhachotropis natator 
DEPTH IN 
METERS 
TOTAL NO. 
SAMPLES 
NO. 
POSITIVE 
SAMPLES 
PER CENT 
POSITIVE 
Night 
600-900 
4 
0 
0 
900-1100 
3 
3 
100 
Day 
600-900 
11 
6 
54.5 
900-1100 
8 
6 
75 
Eurythenes obesus Shoemaker, 1956: 177- 
178; Barnard, J. L., 1961: 38-39, fig. 8. 
A total of 6 specimens of this species was 
recovered from 5 samples ranging in depth 
from 685 to 1000 m. The possibility of de- 
mersal activity was suggested by Barnard (1961 : 
26). He reported that Eurythenes obesus had 
been taken in both pelagic and benthic samples, 
stipulating the possibility of benthic gear cap- 
turing pelagic organisms. The individuals re- 
covered in this present study were certainly 
many meters above the bottom. Gut analyses 
revealed debris and what appeared to be si- 
licious sponge spicules which may indicate 
benthic feeding. If this species does feed on 
the bottom it must migrate vertically some 500 
to 600 m, as indicated by the capture depths 
and the fact that the floor of the Santa Catalina 
Basin is at a depth of 1436 m. 
Paracallisoma coecus (Holmes) 
Scopelocheirus coecus Holmes, 1908: 500- 
502, figs. 10-12; Barnard, J. L., 1954^: 54, 
pis. 4 — 5. 
Paracallisoma coecus Barnard, J. L., 1954£: 
57. 
This species, known only from the waters 
off the coast of southern California, occurred 
to 1100 m. A total of 56 individuals was re- 
covered from quantitative samples. J. L. Bar- 
