Pacific Salpidae — YoUNT 
315 
Fig. 22. Thetys vagina, solitary form, a. Whole animal, dorsal aspect; b, test, right side; c, test, ventral surface; 
d, schematic cross section of the test at gut level. 
Salpa bigibbosa Quoy and Gaimard, 1824: 505. 
Salpa gibbosa Quoy and Gaimard, 1824: 506. 
Salpa infandibuliformis Quoy and Gaimard, 
1824: 508. 
Salpa costata-tilesii Traustedt, 1885: 379; Oka, 
1915: 30. 
Salpa sp. n. sp. [?] Herdman, 1888: 62. 
Jasls tilesii Lahille, 1890: 11. 
Salpa (Jasis) costata-tilesii Apstein, 1894^.* 50. 
Salpa tilesii- costata Ritter, 1905 : 70. 
Salpa vagina Ihle, 1911: 587. 
Salpa {Thetys) vagina Metcalf, 1918: 121; Se- 
well, 1926: 98; Stiasny, 1926: 446; Berrill, 
1950: 299. 
SOLITARY form: One specimen examined 
with length of 123 mm. without projections 
(Fig. 22). Test: Firm and thick except on 
inturned lips and on cloacal siphon; large 
spines occuring irregularly over whole sur- 
face; a prominent posterior projection on each 
side of cloacal siphon, containing tube of 
mantel epithelium with no sucker; dorsal de- 
pression limited by a groove on each side of 
a raised middle region, the whole limited by 
broad limiting elevations; shallow lateral de- 
pression; midventral elevation raised over gut 
and chin as swellings; transverse groove at 
base of dorsal lip, continuing laterally to angle 
of mouth; one swelling on each side of dorsal 
surface posterior to transverse groove; base 
of ventral lip with a weak circular depression; 
transverse groove at base of cloacal siphon; 
one short, weak, longitudinal depression 
crossing each side of chin ventrally. Muscles: 
Twenty weakly developed muscles (number 
varies from 16 to 22 according to Thompson, 
1948); all interrupted dorsally and ventrally, 
often elsewhere, accompanied by prominent 
blood vessels; muscles not extending to ven- 
tral surface, but blood vessels do; M I-IV or 
VI converge dorsally. Ciliated groove: Forming 
a large open loop. Viscera: Gut large, com- 
pact, in state E (Ihle and Ihle-Landenberg, 
1933); located far anteriorly, at about the 
posterior third of body; endostyle broad, 
straight; stolon coursing anteriorly, bending 
and coursing posteriorly on left side of gut 
(Traustedt, 1885). 
