SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
Observations . — Our figure is drawn from a cast of a nucu- 
loid shell which, by its depressed umbo, apparent absence of a 
ligament-pit and constricted posterior angle, falls into the 
genus Palceoneilo as defined by J. Hall. The present specimen 
is exactly comparable in outline with Conrad’s figure of P. con- 
stricta, and it further shows a characteristically large posterior 
adductor impression. In the absence of external ornament 
there is some slight doubt as to its specific identity. 
This species ranges through the Devonian of North 
America. 
Horizon and Locality . — Silurian (Melbournian). In the 
shale of the Yarra Improvement Works, S. Yarra. [7923.] 
P alceoneilo cf. brevis, J. Hall, P. VI., Fig. 55. 
Palceoneilo brevis, J. Hall, 1870, Prelim. Notice Lamell. 2, 
p. 10, Id. 1885, Pal. N. York, Vol. V., Pt. I. Lamell. II. 
p. 342, PI. L., Figs. 24-33. 
Observations . — Our specimen is comparable with the above 
form in having a short, ovate valve, ornamented with fine con- 
centric strise. The posterior margin is not perfect, but the 
depressed surface in front of the umbonal ridge is sufficient 
indication of the presence of a constriction on the basal margin 
of the shell. In the absence of more perfect specimens 
it will be safer to indicate the species with some reserve. J. 
Hall’s examples were from the Chemung Group (Up. Devonian) 
of the States of New York and Pennsylvania. 
Horizon and Locality . — Silurian (Melbournian). In pale 
mudstone, Merri Creek, sects. 2 and 3, Ivalkallo (Kinlochewe), 
coll. Geol. Surv. Viet. B b 3. [968.] 
Palceoneilo cf. tenuistriata, J. Hall, PI. III., Fig. 56. 
Palceoneilo tenuistriata , J. Hall, 1885, Pal. N. York, Vol. 
V„ Pt. I. Lamell. II., p. 336, PI. XLIX., Figs. 1-12, 14; PI. 
XCIII., Fig. 13. 
Observations . — Our figure is taken from a wax squeeze of 
a mould of the external surface of shell. In the regularly and 
finely striate surface, and the obovate form of the valve it can 
be closely compared with J. Flail’s species cited above. The 
strongest points of difference are, the obsolescence of the postero- 
umbonal sulcus in our form, and the central position of the 
beaks, although one example figured by Hall approaches ours 
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