NOTES ON TESTACHA FROM THE PLEISTOCENE MARL 
OF MOWBRAY SWAMP, NORTH-WEST TASMANIA. 
By Frederick Chapman, A.L.S., F.R.M.S., Palewontologist to the 
National Museum, Melbourne. 
(Plates I., II.) 
The object of the present note is to record one or two additions 
to the list of mollusca given by Dr. F. Noetling*, and to describe 
the occurrence of some Ostracoda new to Tasmania. For the oppor- 
tunity of examining a sample of this marl from the Mowbray Swamp 
I am indebted to Dr. T. 8. Hall, M.A., and Mr. T. Stephens, M.A. 
From this deposit the remains of a giant marsupial, the Nototherium 
tasmanicum of Mr. H. H. Scottt, were obtained, whilst Dr. Noetling 
has dealt generally with the characters of the mud deposit. 
Quoting from Dr. Noetling (loc. cit., p. 125), ‘ The Mowbray 
Swamp is about 12 miles west of Smithton, and, apparently, fills 
up a shallow depression of the surface. Probably it represents an 
old river course, which once had an outlet to the sea, but which 
subsequently became blocked up by sand. At present the ‘ swamp ’ 
is divided from the sea by a narrow strip of sand, on which low 
dunes are rising towards the coast. There is hardly any natural 
fall from the swamp to the sea, and the vegetabilic mould, or, better 
said, peat, which fills up the depression, is completely waterlogged. 
The thickness of the peat layer is not exactly known yet, but along 
the edge of the swamp, where drainage work has been extensive, 
it reaches about 25 feet to 30 feet. To me it seems very probable 
that the deepest point of the firm bottom on which the peat rests, 
is below sea level, and this would account in some way for the 
sluggishness of the fall.” 
The material here examined, chiefly for ostracoda, of which, 
by the way, no species have yet been recorded, is a pale yellowish- 
grey marl, of a loose, pulverulent nature. 
The mollusca met with in the present sample are :— 
Sphervum tasmanicum, T. Woods sp. 
Pisidium tasmanicum, T. Woods. 
Bythinella nigra, Quoy and Gaimard sp. 
Assiminea tasmanica, T. Woods. 
Bulinus tasmanicus, T. Woods sp. 
Amphipeplea subaquatilis, Tate sp. var. neglecta, Petterd. 
Vitrina malligani, Pfeiffer. : 
e 
* Proc. R. Soc. Tas., 1911, pp. 124-133. List of mollusea on p. 128. 
+ Tasmanian Naturalist, vol. ii., No. 4, 1911, p. 64. 
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