PACIFIC TUNICATA OF U.S. NATIONAL MUSEUM 39 



fourtli or liflli transverse vessel. Fertilized eggs 3 to 7, or embryos in 

 various stages of development found in incubatory pouches of zooids 

 examined. Stomach situated near the middle of abdomen, with 20-35 

 longitudinal plications on the surface, some somewhat irregularly ar- 

 ranged. Esophagus rather thick, may be slightly swollen near pos- 

 terior end just before it enters cardiac end of stomach in some zooids of 

 colonies from the Gilbert Islands. Proximal end of rectum swollen 

 considerably and distinctly constricted from midintestinal portion oc- 

 cupying posterior end of intestinal loop, but no distmct caecum is 

 formed there. Circumintestinal gland a whitish glandular tissue on 

 the rectum, extending upward from the level of middle of stomach 

 for the distance of the stomach length. Ovary situated above testis; 

 testicular follicles attain 45 in larger postabdomens, but may be fewer 

 than 8 m smaller ones. 



Embryos rather large, up to 1100 /x in length. Attachment proc- 

 esses 3, cup-shaped, roundish in outline, and arranged lineally; stalks 

 long and slender, in a fully developed stage their distal ends may fail 

 to reach the attachment discs (fig. da). Four pairs of ampullae are 

 seen in an earlier stage (fig. 8e), increasing in number (fig. db) with 

 development until liberated from the body surface of the embryonal 

 trunk as many small bulbs scattered in the anterior portion of the 

 embryonal test. In 3 embryos examined these bulbs are arranged as 

 follows : 



12 3 2 



(1) 19 ampullae in total. Dorsal 1 11 Ventral 



12 3 2 



(2) Younger stage (fig. 96), 22 am- 12 4 2 



pullae in total. Dorsal 1 11 Ventral 



13 4 2 



(3) Older stage (lig. 9a), 33 ampullae 3 4 4 3 



in total. Dorsal 1 13 Ventral 



2 3 4 5 



Sensory organs situated in posterior part of the trunk; pigment flecks 

 arranged anteroposteriorly or somewhat obliquely in advanctnl stiiges. 

 Tail held on the left side of trunk. 



IIk:marks. — The present specimens conform well to both the original 

 form from the 8ihoga collection and that described by Van Name 

 from Philippine waters. The longitudinal plications on the stomach 

 are rather numerous in some of the present specimens and tlius the 

 range of variation is extended to 18-35. A7naroucium, sp. all', multi- 

 plicafum described by Tokioka (1953a) from Sagami P)ay, Japan, is 

 evidently identical with multipllcatmn itself; the longitudinal plica- 

 tions on the stomach are numerous enough and no distinct caecum is 

 formed at the proximal end of rectum. The structure of the larva in 

 that form is essentially the same as found in larvae in the present 



