SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
Affinities. — Both Macrodon liamiltonice, J. Hall, of the 
Hamilton Group of N. America* and Macrodus villmarensis , 
Beushausen, from the upper beds of the Middle Devonian of the 
Rhine areaf bear a general resemblance to our species, but in 
many points of detail they are quite distinct, lacking the boldly 
curving ventral margin, and strong compression of the posterior 
region of the shell seen in the Australian species. 
Horizon and Locality. — Silurian (Yeringian), Wandong, 
Victoria; in yellow sandstone. Type specimen collected and 
presented by Mr. F. P. Spry, after whom tKe species is named. 
[7950.] 
Parallelodon cequalis, sp. nov. Plate IV., Fig. 57. 
Description. — Shell small, elongate oval, rounded and con- 
stricted in front, broader and truncated behind, with a sharp 
umbonal ridge extending from the umbo to the postero-ventral 
margin. Beaks sub-anterior, or nearly central, inflated and 
directed forward. Cardinal line straight; ventral border 
slightly curved and approximately parallel with the hinge- 
line. Three posterior, oblique, lateral teeth visible behind the 
beaks, and close to the cardinal border. 
Measurements. — Length, 12 mm.; height, 7.5 mm.; depth 
of valve, 2.5 mm. 
Observations. — The above species belongs to a type of shell 
of which the “Area scitida ” of McCoy t is an example. That 
species differs from ours in the more extended posterior, and in 
the strong concentric surface ornament; McCoy’s species may, 
however, eventually prove to be more nearly “related to the 
North American Devonian types of this genus. 
Horizon and Locality. — Silurian (Melbournian). In brown 
mudstone, Yarra Improvement Works, S. Yarra. Presented bv 
Mr. F. P. Spry. [7924.] 
? Parallelodon Jdlmoriensis, sp. nov. PI. IV.. Fig. 58, ? fig. 59. 
Description. — Shell small, rhomboid, sub-circular; length 
a little more than the height. Ventral margin boldly rounded; 
both extremities broad, the anterior short and truncate, the 
posterior margin curving upward and forward to meet the 
cardinal line. Beaks prominent, slightly anterior, pointing 
* Prelim. Notice, Lamelli., 2, p. 13, 1870. See also J. Hall, PalaeontT New York 
Vol. V., Pt. T. Lamellibrancliiata, II., 1885, p. 349, PI. LI., Figs. 1, 7, 0, 10. 
t Abhandl. von. Preuss. Landesanst., N. F. Heft., XVII., 1895, p’ 38, PI IV 
Fig. 2. ', 
+ Synopsis of the Silurian Fossils of Ireland, 1846, p. 20, PI. II., Fi<r 6 
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