326 
PACIFIC SCIENCE, VoL VIII, July, 1954 
small size; atrial palp bifurcated; smooth ap- 
pearance of the testis lobes. Moreover, he 
distinguished the form echinata on the basis 
of "the existence of several spiniferous ridges 
on the testa." Sewell (1926) also distinguished 
a spiniferous form and found them to be 
uniformly of a smaller size than Atlantic spec- 
imens. In the POFI collections there are also 
two forms distinguishable on the basis of test 
differences, the one an echinate form, the 
other a smooth form; both are small. There 
are, however, among solitary individuals, in- 
tergrading degrees of echination, but con- 
clusions on the validity of Tokioka’s variety 
and form deserve further study, especially of 
a series of specimens from different oceans. 
Although this species is the most common 
salp of warm seas (Apstein, 1906^), it is not 
one of the better known in regard to test 
structure. Apstein (1906^) figured the ech- 
inate aggregate form well, as did Stiasny 
(1919) and Tokioka (1937). The smooth form 
of both generations was well figured by Sti- 
asny (1926). It is felt, however, that the fig- 
ures in the present report are more thorough 
than previous ones as a result of staining. 
Genus Iasis Savigny, 1816 
Solitary form with five broad, dorsally and 
ventrally interrupted body muscles and with 
a broad M C. Aggregate form with five body 
muscles of which the first is interrupted dors- 
ally and ventrally, the remainder only ven- 
trally; M V is branched into two parts on the 
right side. 
One species, lasts zonaria. 
Iasis zonaria (Pallas) 1774 
Fig. 30^-/ 
Holothurium zonarium Pallas, 1774: 26. 
Salpa polycratica Forskal, 1775: 116. 
Biphora zonaria Bruguiere, 1789: 182. 
Salpa zonaria Chamisso, 1819: 12; Bomford, 
1913: 245. 
Salpa cordiformis Quoy and Gaimard, 1827: 
226 . 
Salpa microstoma Quoy and Gaimard, 1827: 
226 . 
Salpa unicuspidata Blainville, 1827: 116. 
Salpa quadrangularis [.^] Lesson, 1830: 268. 
Salpa tricuspidata [.?] Lesson, 1830: 272. 
Salpa cordiformis-quadratica Vogt, 1854: 7. 
Salpa cordiformis-zonariaTtdiMsiQdit, 1885: 382; 
Oka, 1915: 30. 
Salpa nitida [.?] Herdman, 1888: 81. 
Jasis polycratica Lahille, 1890: 11. 
Salpa {Jasis) cordiformis-zonaria Apstein, 
1894^.' 51. 
Jasis zonaria Heider, 1895: 368. 
Salpa zonaria-cordiformis Ritter, 1905: 76. 
Salpa {Salpa) zonaria Streiff, 1908: 45. 
Salpa {Iasis) zonaria Metcalf, I9I8: 100; Sti- 
asny, 1926: 434; Berrill, 1950: 295. 
Salpa {Jasis) zonaria Sewell, 1926: 88. 
Iasis zonaria Ihle, 1935: 527-529; Tokioka, 
1937: 223; Thompson, 1948: 132. 
SOLITARY form: More than 10 specimens 
examined with length range of 16-51 mm. 
(Fig. 30^-^). Best: Firm, elongate; moderately 
thick; mouth a broad slit; dorsal depression 
extending to base of upper lip, limited by 
dorsal limiting elevations; a lateral ridge on 
each side of latter gradually disappearing an- 
teriorly; posteriorly, lateral ridges ascending 
to pointed, short, dorsal projections; a pos- 
terior ridge extending from the latter ven- 
trally, fusing with its fellow of the opposite 
side midventrally at the longer, unpaired, me- 
dian posterior projection; projections prom- 
inent in lateral view; a deep lateral groove, 
or a wide depression as shown by Brooks and 
Stiasny, gradually forming ventral and ante- 
rior to dorsal posterior projections, continu- 
ing anteriorly to the front third of body; a 
ventrolateral ridge extending from gut swell- 
ing, coursing anteriorly up to ventral lip; gut 
swelling moderately large; midventral ridge 
on posterior region of gut swelling; mid- 
ventral depression coursing anteriorly from 
this to base of lower lip; this depression raised 
slightly in cross section, limited on each side 
by deep grooves; ventrolateral elevation bear- 
ing a ventrolateral ridge (which may be weak) 
