Pacific Salpidae — YoUNT 
caecum forming right and left parts, respec- 
tively, of head of T, intestine forming pos- 
terior shaft of T ; elongate, cylindrical, blood- 
forming organ located on left side, projecting 
from region of caecum dorsally, then bending 
anteriorly (abnormally posteriorly as in the 
figured specimen); stolon forming a slight 
bend and turning posteriorly at region of 
M VI-VIII. 
AGGREGATE FORM: Two Specimens exam- 
309 
ined, with length range of 18-23 mm., with- 
out end projections (Fig. 19c-/). TesL’ Flabby, 
glutinous, without permanent elevations and 
depressions except gut swelling which forms 
a large protrusion almost wholly independent 
of the rest of the body; end projections asym- 
metric, filiform. Muscles: Body muscles closely 
similar to those of R. amboinensis except wider 
and composed of more fibers (Berner, 1954) ; 
three sphincters in dorsal lip, of which the 
Fig. 19. Ritterklla pkteti. a, Solitary form, right side; b, solitary form, left side of embryo (length, 1.3 mm.); 
c, aggregate form, right side; d, aggregate form, mouth musculature of left side from inside; e, aggregate form, 
ciliated groove, lateral aspect; /, aggregate form, ciliated groove, ventral aspect. 
