466 
PACIFIC SCIENCE, Vol. XVIII, October 1964 
scattered and never grouped into papillae. (After 
Clark, 1907.) 
type SPECIES: Trochodota purpurea (Lesson). 
REMARKS: This is a well-defined, cosmopoli- 
tan genus, containing about a dozen species, 
some of which are inadequately described. There 
are three species in Australia, two in New Zea- 
land, and one in southern South America. T. 
dunedinensis from New Zealand resembles T. 
purpurea from South America in many respects, 
and the two species may be related. 
Trochodota purpurea (Lesson) 
Holothuria ( Fistularia ) purpurea Lesson, 1830, 
p. 155, pi. 53, fig. 1. 
Chirodota purpurea Tager, 1833, p. 16; Dujardin 
and Hupe, 1862, p. 616. 
Chiridota purpurea Brandt, 1835, p. 259. 
Sigmodota purpurea Studer, 1876, p. 454 (par- 
ting. 
Chirodota australiana Theel, 1886^, p. 16. 
Chirodota studeri Lampert, 1889, p. 839, pi. 
XXIV, fig. 12. 
Trochodota studeri Ludwig, 1892, p. 359. 
Sigmodota studeri Oestergren, 1898. 
Trochodota purpurea Ludwig, 1898^, p. 83, pi. 
Ill, figs. 43-45; Perrier, 1905, p. 76; Clark, 
1907, p. 123; Clark, 1921, p. 166; Ekman, 
1925, p. 149; Deichmann, 1947, p. 351. 
DIAGNOSIS: Tentacles 10, each with 2-6 pairs 
of digits. Wheels (0.13-0.18 mm diameter) 
scattered in the skin, together with sigmoid 
hooks (0.12-0.13 mm long). Tentacle deposits, 
when present, average 0.078 mm in length, and 
are bracket-shaped, with dichotomously branch- 
ing ends. Colour in life commonly purple. 
MATERIAL EXAMINED: Sta. 73, 8 specimens; 
Sta. 74, 2 specimens; Sta. 77, 1 specimen. 
remarks: The smallest specimen in the col- 
lection is 4 mm in total length, and the largest is 
100 mm. Colour in alcohol ranges from off white 
to light brown or violet. The number of tentacle 
digits varies. Clark (1921) in his key to the 
species of Trochodota stated that species pur- 
purea has tentacles with six digits each. In the 
present collection, one specimen has 12 digits 
per tentacle, and another has eight. Clearly the 
number of tentacle digits is not a reliable diag- 
nostic character in this species. The calcareous 
deposits in the skin have been well described. 
The tentacles in some of the specimens 
contain a number of bracket-shaped rods with 
dichotomously branching ends (Fig. 3, 8). Per- 
rier (1905) stated that the tentacles in his 
material were "totally devoid of calcareous de- 
posits,” while Deichmann (1947), in diagnos- 
ing this species, wrote ". . . no spicules in the 
tentacles.” Ludwig (1898^) illustrated a single 
tentacle rod, and it closely resembles those illus- 
trated here. There is no doubt, then, that ten- 
tacle deposits may be present, perhaps in young 
stages, and become rare or disappear as a speci- 
men grows, as can happen with the wheels and 
hooks in the body wall. 
DISTRIBUTION: Trochodota purpurea is re- 
corded from the southern tip of South Amer- 
ica and the Falkland Is., to depths of about 
50 m. Habitat includes sand, shelly bottom, 
and holdfasts and fronds of seaweed, especially 
Macrocystis. 
Genus Taenio gyrus Semper, 1868 
Sigmodota Studer, 1876. 
DIAGNOSIS: Tentacles peltato-digitate, 10 or 
12. Digits five to seven pairs per tentacle, the 
terminal pair being the longest. Calcareous de- 
posits are wheels gathered into papillae, and sig- 
moid hooks (about 0.2 mm long), scattered in 
the skin. No miliary granules in radial longi- 
tudinal muscles. 
TYPE species: T aenio gyrus australianus 
Stimpson. 
remarks: This is a small genus containing 
about six species. Three species are known from 
Australia, one from Japan, one from Hawaii, 
and one from the southeast Pacific Ocean. 
Taeniogyrus lies intermediate between Chiri- 
dota (wheels and occasionally curved rods, no 
sigmoid hooks) and Trochodota (wheels, and 
sigmoid hooks, the wheels not grouped into 
papillae ) . 
Taeniogyrus contortus (Ludwig) 
Chiridota contorta Ludwig, 1874, p. 80, pi. VI, 
fig. 6; Lampert, 1885, p. 234; Theel, 1886^, 
pp. 16, 33, pi 2, fig. 2; Theel, 1886£, p. 20; 
Lampert, 1889, pp. 851, 853. 
Sigmodota purpurea Studer, 1876, p. 454; Stu- 
der, 1879, p. 123. 
