Pacific Salpidae — YoUNT 
Salpa chamissonis Brooks, 1893: 376. 
Salpa {Cyclosalpa) affinis Apstein, 1894^.* 4; 
Metcalf, 1918: 27; Sewell, 1926: 74; Ko- 
mai, 1932: 70. 
SOLITARY FORM: One specimen examined 
with length of 54 mm. (Fig. Aa). Test: Thin, 
glutinous, attached at mouth and cloacal 
opening; no definite elevations or depres- 
sions. Muscles: Six body muscles: M I and 
II interrupted dorsally and ventrally, M III- 
VI interrupted ventrally, continuous dorsally; 
X sending one branch anteriorly (broken in 
this specimen) which is continuous with pos- 
terior branch of M VI; x continuing far ven- 
trally; X and y converging laterally but not 
touching; M I joining mouth muscles. Ciliated 
groove^ ganglion and eye: Ganglion and eye 
anterior to M I, just above anus; ciliated 
groove far anterior to them, highly convo- 
luted. Viscera: Esophagus forming a spiral at 
ventral level of M VI and x; a single posterior 
caecum (actually double, appearing single, 
according to Komai, 1932) connecting to in- 
testine which courses antero-obliquely with 
gill; anus opening just anterior to M I; gill 
ending anterior to M C; a large oval body 
located on each side between M IV and V. 
It is conspicuous with stain and probably 
is a light organ (this is not mentioned in past 
descriptions). 
AGGREGATE FORM: Three specimens ex- 
amined with length range of 18-33 mm. (Fig. 
Ah). Test: Closely attached at mouth, cloacal 
opening, on peduncle and intestine (Metcalf, 
1918, figures it as very loose on latter two 
structures); test with no definite elevations 
or depressions, glutinous, thin, may be far 
separated from mantle; peduncle short, broad. 
Muscles: Four body muscles; all interrupted 
ventrally, continuous dorsally and separated 
from one another except IV and x; M I 
joining with mouth muscles; M C forming 
anterior peduncle muscles, posterior peduncle 
muscles independent; total of four muscles 
in peduncle, two anterior and two posterior; 
M I sending off two anterior branches; x and 
285 
Fig. 4. Cyclosalpa affints. a, Solitary form, left side; 
h, aggregate from, right side. 
