TESTACEA FROM THE PLEISTOCENE MARL OF MOWBRAY SWAMP. 
Of these, Assiminea tasmanica and Amphipeplea subaquatilis, 
var. neglecta, are not recorded by Dr. Noetling. The genera As- 
siminea and Bythinella are strong indications of the presence of 
tidal influence in this swamp. This bears out Noetling’s conclusions, 
since he states that “ Probably it represents an old river course 
which once had an outlet to the sea.” (loc. supra cit.). 
The ostracoda are new to this locality and deposit. They are 
referable to— 
Candona lutea, King, and 
Limnicythere mowbrayensis, sp. nov. 
NOTES ON THE MOLLUSCA. 
PELECYPODA. 
SPH&RIUM TASMANICUM, T. Woods sp. 
Cyclas tasmanca, T: Woods, 1876, Proc. R. Soc., Tasm., for 
1875, p. 82. Spherium macgillivrayi, E. A. Smith, 1881, Proce. 
Linn. Soc., Lond., Zool., vol. XVI., p. 305, pl. VIL., fig. 34. 
Tenison Woods gives the length of the type shell as 9mm.; 
whilst the largest of our fossil form is only 4mm. The general 
colour of the shell, and the silvery bands mentioned by that author, 
are still visible on the fossil specimens. 
As regards the synonymy of the species, there is no doubt of the 
identity of Mr. Edgar Smith’s species with the earlier S. tasmanicum. 
This conclusion is based not only on a comparison of the description 
of both shells and the figures of S. macgillivrayi, but also from an 
examination of many examples from different localities in Victoria 
and Tasmania, in the Dennant collection. Moreover, the young 
of S. tasmanicum, from Lake Connewarre, near Geelong (labelled 
in the Dennant collection as a Pisidium, is identical with our 
Pleistocene fossils from the Mowbray Swamp. Further than this, 
the Spherium tasmanicum is the only species known from Tasmania, 
and has been previously identified by Dr. Noetling from that 
locality. 
Pistprum TAsMANIcUM, T’. Woods. 
Pisidium tasmanicum, T. Woods, 1876, Proc. R. Soc., Tasm., for 
1875, p. 81. 
The length of the shell in this species, according to T. Woods, 
is from 24mm. The fossil examples are about 1.75mm. in length. 
In the original description of this species, there is no mention of 
other surface-ornament than the concentric strize. The present 
specimens, however, show numerous very fine radial striz crossing 
the concentrics, when viewed under the microscope by oblique 
incident light. This species has been recorded from the same 
locality by Dr. Noetling. 
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