The Holothuroidea Collected by the Royal Society Expedition 
to Southern Chile, 1958-1959 
D. L. Pawson 1 
ABSTRACT: The holothurians collected by the Royal Society Expedition to south- 
ern Chile, totalling 180 specimens, are described. Ten genera (of which one is new) 
and ten species are represented. Neopsolidium n.g., type species Psolidium con- 
vey gens (Herouard), is erected to accommodate those species in the genus Psolidium 
(sensu lato) in which the dorsal plates are reduced to a diameter of about 0.4 mm. 
The holothurian fauna of southern Chile is generalised, containing few restricted 
species, and sharing many elements with distant subantarctic islands and with 
Antarctica. 
During late 1958 and early 1959 an expedition 
sponsored by the Royal Society carried out ma- 
rine and terrestrial observations and collections 
in southern Chile. Stations were established in 
three separate areas, namely: 
1. Isla Chiloe (approx. 42° S) 
2. Puerto Eden to Punta Arenas (approx. 
49° S to 52° S) 
3. Isla Navarino and southern regions (ap- 
prox. 55° S). 
These three areas, considered together, were ex- 
pected to provide a good picture of the changes 
in flora and fauna along the Patagonian coast- 
line. The present paper contains an account of 
the holothurians collected by the marine biol- 
ogist to the expedition, Prof. G. A. Knox, of 
Canterbury University, Christchurch. 
A total of 180 specimens of holothurians were 
collected, and these comprise 10 genera and 10 
species. The collection represents a good cross- 
section of the known fauna, although a number 
of species, hitherto regarded as common, were 
not found. 
The shallow-water holothurian fauna of south- 
ern Chile is not large in terms of species, al- 
though a wide variety of genera are represented. 
This is particularly true for the order Den- 
drochirotida. Previous authors such as Ludwig 
(1898*, 1898£), Perrier (1905), Ekman (1925), 
1 Department of Zoology, Victoria University of 
Wellington, Wellington, New Zealand. Manuscript 
received September 27, 1963. 
and Deichmann (1947) have provided a clear 
picture of the composition of the fauna. It is 
unlikely that many new shallow-water species 
will be taken from this region. 
I am grateful for the opportunity to study this 
most interesting collection, and I would like to 
thank Prof. G. A. Knox and the Royal Society 
for making this material available to me. 
LIST OF SPECIES COLLECTED 
Order Dendrochirotida 
Family Phyllophoridae 
Subfamily Thyonidiinae Reding and Pan- 
ning, 1954 
Athyonidium chilensis (Semper) 
Family Cucumariidae 
Subfamily Cucumariinae 
Cladodactyla crocea (Lesson) 
Stereoderma laevigata (Verrill) 
Pseudocnus duhiosus ( Semper ) 
Subfamily Colochirinae Panning, 1949 
Tr achy thy one lechleri (Lampert) 
Family Psolidae 
Neopsolidium convergens (Herouard) 
P solus patagonicus ( Ekman ) 
Order Apodida 
Family Chiridotidae 
Chiridota pisanii ( Ludwig ) 
Trochodota purpurea (Lesson) 
Taenio gyrus contortus (Ludwig) 
Order Molpadida — -none 
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