June, 1953 
THE SOUTH AUSTRALIAN NATURALIST 
Sixty-three 
AN INTERESTING MARINE SPIDER, DESIS KENYONAE 
POCOCK FROM SOUTH AUSTRALIA 
by H. WOMERSLEY , 
South Australian Museum 
Spiders of the genus Desis are 
not common. They are to be 
found on low rocky reefs crawling 
over the rocks when exposed at 
low tide. 
Closely allied to the European 
water spider Argyroneta aquatica, 
they have somewhat similar habits, 
but instead of making an inverted 
silken bell attached to weeds, they 
live in the crannies of the rocks 
which they apparently fill with 
air, as does Argyroneta with her 
bell, when submerged by the tide. 
They are quite at home in the 
water itself. 
Recently J have been indebted 
to Mr. S. E. Rowe for a male speci- 
men of Desis kenyonae which he 
found walking over the rocks on 
a small island off Pondalowie Bay, 
Yorke Peninsula, South Australia, 
on 5th January, 1953. 
Although the present account is 
the first published record of this 
spider for South Australia, it has 
been known to me for some years 
from specimens collected by my 
son (J. S. Womersley) on the reef 
at Noarlunga, 25th December, 
1935, while in the Museum collec- 
tion are several specimens from 
Sellick Beach, March, 1936, col- 
lected by Mr. H. M. Hale. 
The species was originally col- 
lected from San Remo, Western- 
port Bay, Victoria, by Miss Ken- 
von. 
j 
In his description in the Proc. 
Zool. Soc. London, 1902, vol. 2., I 
p. 102 Pocock quotes from Miss 
Kenyon the following: 
“During a recent stay at San 
Remo, while turning over stones 
at low water in search of Mollusca, 
I noticed what seemed to be the 
sea-worn shell of a Crepidula. 
Upon detaching the shell from the 
partially submerged rock to which 
it adhered, I found underneath it 
the spider with its legs drawn back- 
wards and its head concealed un- 
der a sheet of web which exactly 
resembled the septum , of the 
valve of a Crepidula although the 
shell itself was that of an Anomia. 
The spider was conspicuous from 
the intense blue of its abdomen 
and the vivid red of its cephalo- 
thorax. The shell was apparently 
fixed to the ground by means of a 
silken attachment, since the shell 
had to be removed by the inser- 
tion of the point of a penknife/’ 
Mr. Pocock (loc. cit.) also gives 
a key for the separation of the 
known species only two of which, 
marina Hector and kenyonae , are 
Australian. Since then a third 
species hartmeyeri was described 
bv Simon from the Michaelson 
and Hartmeyer Expedition to 
South West Australia. 
The three known Australian 
species may be separated as 
follows: 
1. Eyes of both anterior and 
posterior rows very unequally 
spaced, the distance between 
medians and laterals far 
greater than between them- 
selves; protarsus of legs II, 
III, and IV with a pair of 
spines on proximal side of 
