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PACIFIC SCIENCE, Vol. IX, April, 1955 
Fig. 4. Cyclosalpa strongylenteron , solitary generation, 
oral musculature, dt, Dorsal tubercle; gg, dorsal 
ganglion; IM, intermediate muscle; L 1 -L 5 , sphincters of 
the lower lip; m, oral opening; OR, oral retractor; 
Ui-U 4 , sphincters of the upper lip; VL, ventral languet. 
Light organs: It could not be determined 
whether or not light organs were present. 
Muscles: (Figs. 3 and 4) There appear to be 
seven body muscles arranged in a manner 
much more complicated than in other species 
of the genus. All the body muscles are in- 
terrupted ventrally and appear to form two 
bundles dorsally. 
The oral musculature could be determined 
on the embryo taken at station 35-110.60, it 
is more complicated than that of any of the 
other cyclosalpas (Fig. 4). There are five 
sphincters on the lower lip and four on the 
upper lip. There is a single oral retractor which 
passes forward external to the intermediate 
muscle and bifurcates into a dorsal and a 
ventral portion. The dorsal portion continues 
forward to form the first ventral oral sphincter 
(Li), midway along its course a small muscle 
branches off to form L 2 . The ventral branch 
of the oral retractor gives off a thin branch, 
just after its formation, which continues for- 
ward to form L3. The remaining portion of 
the ventral branch then bifurcates to form 
L4 and L5. The first two sphincters of the 
upper lip, Ui and U 2 , originate from the first 
sphincter of the lower lip midway between 
its origin and the origin of L 2 . U3 is formed 
from two portions, one coming from U4 just 
as it emerges from under the oral retractor 
and the other from the oral retractor just 
before its bifurcation. A branch from the 
ventral portion of the oral retractor and an 
independent muscle which runs parallel to the 
intermediate muscle join under the oral re- 
tractor and continue dorsally as U4. Near the 
dorsal midline U4 gives off a branch which 
turns posteriorly and joins the intermediate 
muscle in the region of the dorsal ganglion. 
Fig. 5. Cyclosalpa strongylenteron , gill and gut of 
solitary generation, an, Anus; c, caecum; dt, dorsal 
tubercle; G, gill; int, intestine; oe, oesophageal 
opening. 
The atrial musculature appears to be much 
like that of the solitary C. afftnis. 
Dorsal tubercle: The dorsal tubercle is almost 
identical with that of the aggregate form, a 
condition approached but not obtained in 
C. afftnis. 
Internal structure: The gut, as is typical of 
all solitary cyclosalpas, is dorsal to the gill, 
but uniquely it overlays just slightly less than 
half the length of the gill (Fig. 5). The wide 
hairing oesophageal opening lies at the ven- 
