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PACIFIC SCIENCE, Vol. IX, July, 1955 
from moss and lichens, 27 September, T. E. 
Woodward, one immature female; Binna 
Burra, Lamington Plateau, from leaf mould 
gathered in rain forest, 28 September, T. E. 
Woodward, one immature female. The spec- 
imens are at present housed in the Canterbury 
Museum. 
The description given above will need con- 
siderable amplification when mature spec- 
imens are available for examination but the 
structure of the tarsal claws is sufficient to 
separate this species from sorenseni as this has 
been found to be constant throughout the 
range of specimens of the latter species which 
have been examined, both adult and im- 
mature. The occurrence of these two closely 
related species, separated by over a 1,000 
miles of open sea, is of great interest and adds 
yet another example to the already lengthy 
list showing the close affinity of the New 
Zealand fauna with a section of the Australian 
fauna. If, as many geologists believe, the last 
possible land link between these two areas 
was in the late Mesozoic, the rate of specia- 
tion for many groups must be extremely slow. 
NOTES ON THE BIOLOGY OF 
Gradungula sorenseni 
These spiders are to be found in the 
forested areas of the west coast of the South 
Island of New Zealand and also on Stewart 
Island. In all these areas the rainfall is high 
and the forest is wet continuously. It would 
appear that the Australian species, also, is 
limited in distribution to similar forest con- 
ditions. 
The spiders are nocturnal, and are found 
during the daylight hours sheltering beneath 
logs or small pieces of bark and twigs on the 
forest floor. At such times they are usually 
sluggish and the legs are held close to the 
body. While thus quiescent the abdomen is 
usually covered with a number of small drop- 
lets of water which cling to the hairs. Field 
observations supported by laboratory experi- 
ments would indicate that the species is 
extremely susceptible to dryness and requires 
a high relative humidity for survival. 
It is noteworthy that no sign of any silken 
web, or in fact any silken structure at all, has 
been found associated with the spiders in the 
field. Observations carried on over a period 
of six months under laboratory conditions 
with both males and females have shown only 
the occasional use of a drag line. Food in the 
nature of flies and other small insects was 
readily accepted and was captured by hunt- 
ing, although the distance from which the 
prey was observed was short, rarely more than 
5 or 6 inches. The use of the claws of the 
first two pairs of legs in the capture of prey 
was only observed in one instance when the 
superior claws were flexed against the tarsal 
segment to hold a harvestman ( Nuncia spj, 
but it was released without being killed. 
No mating behavior has been observed and 
the appearance and structure of the egg-sacs 
and sperm web are unknown. 
NOTES ON THE INTERNAL ANATOMY OF 
Gradungula sorenseni 
Digestive System: The thoracenteron is of the 
"classic” type, with four pairs of unbranched 
diverticulae extending laterally and down- 
wards into the coxae of the four pairs of legs. 
There are from 12 to 14 large multicellular 
pyriform glands within each maxilla which 
open from a circular sieve plate on the inner 
margin near the base. 
Excretory System: A pair of biramous Mal- 
pighian tubes open into the gut anterior to 
the stercoral pouch. The coxal glands are well 
developed. There is a single outlet for each 
gland situated at the base of the coxae of the 
first pair of legs. The labyrinth runs back 
from a terminal saccule as a straight tube, 
into which a small accessary saccule opens at 
about the level of the third pair of legs. The 
labyrinth then distends above coxa 4 before 
turning down to run back to the opening on 
the coxae of the first pair of legs. Dorsal and 
ventral "dips” are present on this latter por- 
tion in the region of coxae 3 and 4. 
