Two New Doliolids from the Eastern Pacific Ocean 1 
Takasi Tokioka 2 and Loe Berner 3 
The material upon which this report is 
based was collected during the Shellback 
Expedition carried out by Scripps Institution 
of Oceanography in 1952. This expedition 
conducted its work in the east central Pacific 
Ocean off Central America and northern 
South America. While the authors were exam- 
ining the many plankton samples they found 
two unusual doliolids. These specimens were 
from samples taken in the waters off Peru. 
The specimens are all gonozooids; and al- 
though they are not in a good state of preser- 
vation, the arrangements of muscles, alimen- 
tary organs, and gonads have been determined 
by close examination, after staining with Rose 
Bengal. One of the two forms belongs to the 
genus Doliopsoides established by Kruger 
(1939: 138-139). This genus, in the appear- 
ance of the musculature, shows an interme- 
diate state between the Cylomyaria and the 
Desmomyaria. The other form belongs to the 
genus Doliolina. Both forms differ from any 
previously described species known to us and 
we consider them to be new species. 
This is the first reported occurrence of the 
genus Doliopsoides from the Pacific Ocean and, 
indeed, is the first report of the genus since 
it was described by Kruger. At present the 
known distributions of D. horizoni and of D. 
undulatum are limited to only two stations. 
1 Contribution from Scripps Institution of Ocean- 
ography, New Series No. 975. This work was supported 
in part by grants from the Rockefeller Foundation and 
the Office of Naval Research. Manuscript received 
October 23, 1956. 
2 Present address: Seto Marine Biological Labora- 
tory, Japan. 
3 Scripps Institution of Oceanography, University 
of California, La Jolla, California. 
Doliopsoides horizoni new species 
Fig. 1 
Three gonozooids are dealt with here. All 
were found in the sample from station SB- 115 
located at 8° 16' S., 83° 42' W. They are 3-9 
mm., 4.6 mm., and 5.2 mm. in length. One 
additional specimen was taken at station SB- 
118 located at 9° 49' S., 83° 02.5' W. The 
body is roughly barrel-shaped with the oral 
aperture at the anterior end and the atrial 
aperture at the posterior end of the body. 
Both apertures are rather wide and fringed 
with a narrow margin which is, apparently, 
without lappets. The test is of moderate 
thickness, very soft, and easily stripped from 
the body. The mantle is extremely thin and 
delicate. The muscles are rather narrow, espe- 
cially I, VII, and VIII. Muscles I through IV 
and VIII form complete hoops. The first and 
seventh intermuscular zones are narrow while 
the second is quite wide. Muscle V runs 
obliquely from the posteroventral to the an- 
terodorsal side and is widely interrupted at 
the middorsal line. Each dorsal end of muscle 
V turns backwards for a short distance and 
then runs obliquely to the posteroventral side. 
These parts represent muscle VI and are ar- 
ranged parallel to muscle V. They are not 
continuous across the mid-ventral line. There 
is a short section on each of the ventral ends 
of muscle VI which turns slightly forward. 
Each of the ventral ends of muscle VII passes 
external to muscle VI on the side of the body. 
Muscle VII ends slightly below the mid- 
ventral line, just after crossing muscle VI. In 
addition to these muscles there are two nar- 
row, short connecting muscles (lateral longi- 
tudinal muscle, 1.1. m.) between muscles IV 
135 
