Pelagic Tunica ta- — B ary 
109 
FIGS. 9, 10. lash zonaria , solitary and aggregate 
forms. 
Salpa democratica mucronata Ritter, 1905; Rit- 
ter and Byxbee, 1905 
Thalia democratica Metcalf, 1918; Thompson, 
1948; Sewell, 1953 
Initial collections of several hundred speci- 
mens were made at Stations 292, 301, and 304. 
Twelve days later, many thousands were col- 
lected from Stations 322 and 326, south of 
Cook Strait, in both surface and oblique tows. 
The test is thickened, and often with protu- 
berances. In solitary forms (Fig. 11) the muscles 
are continuous ventrally. Posteriorly the test 
protrudes in two long (up to the length of the 
body) and several smaller processes. In aggre- 
gate forms (Fig. 12) the test is greatly thick- 
ened, and with intruding tubular processes. The 
muscles are widely interrupted ventrally. 
Solitary forms (including processes) ranged 
from 9.5 to 27.0 mm., and aggregate forms, 
from 4 to 16.5 mm. in length. Among the ag- 
gregate forms, an estimated 4 per cent pos- 
sessed tests up to four times thicker than usual 
which made the body large and almost spherical. 
Genus PEGEA Savigny 
Pegea confoederata Forskal 
Salpa quadrata Herdman, 1888 
Salpa confoederata scutigera Ritter, 1905; Rit- 
ter and Byxbee, 1905 
Pegea confoederata Metcalf, 1918; Dakin and 
Colefax, 1940; Fraser, 1947; Thompson, 1948; 
Sewell, 1953 
One specimen, a solitary form (Fig. 13) oc- 
curred in an oblique ( 100-0 m.) haul at Station 
326. 
The specimen was approximately 35 mm. 
long, but was somewhat damaged anteriorly. 
The test is fairly rigid, especially in the portion 
about the alimentary "nucleus.” Four dorsal 
muscles are arranged in two pairs, forming 
"X’s”; neither pair reaches the lateral margins 
of body. Ventral muscles are absent. 
It is perhaps unusual that the only specimen 
captured should be the solitary form when it is 
recorded as rarer than the aggregate form (Rit- 
ter, 1905; Ritter and Byxbee, 1905; Metcalf, 
1918; Thompson, 1948). Sewell, on the other- 
hand, saw numerous solitary forms in the Gulf of 
Aden and indicates they were probably brought 
to the surface from deeper water by upwelling. 
The species is a warm water one (Thompson, 
Sewell) and occurred together with subtropical 
Copepoda, e.g., Sapphirina spp. in the Mew Zea- 
land sample. 
Genus Salpa Forskal 
Salpa fusiformis f. as per a Chamisso 
Salpa echinata Herdman, 1888 
Salpa fusiformis f. echinata Ritter, 1905 
Salpa fusiformis f. aspera Metcalf, 1918; Thomp- 
son, 1948 
FIGS. 11, 12. Thalia democratica , solitary and ag- 
gregate forms. 
