SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
Horizon and Locality . — Silurian (Yeringian). MacMahon’s 
Creek, Upper Yarra. Coll, by Dept, of Mines (3780) 
[2263], Another specimen, probably related to the above 
species, was presented to the National Museum by Mr. R. Jacob 
in 1867. This was found at the Caledonian Diggings, One Tree 
Hill, Christmas Hills, in strata apparently of about the same 
horizon as that of the type specimen. In this example the shell 
is higher than the figured type, but this difference may be 
due to compression; the concentric furrows also are not so well 
marked. [7880.] 
Genus Paracardium, Barrande, 1881. 
Parcicardium filosum, sp. nov. PI. I., Figs. 15, 16. 
Description. — Shell sub-trigonal, the beaks prominent, 
ventral margin rounded and expanded. Surface contour well 
arched, especially in the umbonal region and towards the 
ventral margin. Surface ornament consisting of about 22 fine, 
flattened riblets, grooved medially. Cardinal line not perfectly 
preserved, but apparently less extended than in the previous 
genus. 
Affinities. — The small size of the shell, together with the 
prominent, incurved umbones, and the sub-truncate posterior, 
show this fossil to belong to the genus Paracardium. It closely 
approaches Barrande’s P. filifemm* in surface ornament, but 
differs in the more regular proportion of the fine and coarse 
riblets. The Bohemian examples occurred in the Silurian 
(Stage E). 
Measurements . — Height, 7 mm.; length, 8 mm. 
Horizon and Locality. — Silurian (Yeringian). Starvation 
Creek, Upper Yarra. Coll. Geol. Surv., Victoria (3779). 
[7881.] 
Genus Pr^elucina, Barrande. 
Prcelucina ancilla, Barrande. PI. VI., Figs. 88, 88a. 
Prcelucinci ancilla, Barrande, 1881, Syst. Sil. Boheme, Vol. 
VI., p. 280, PI. LXVIII. 
Observations. — The occurrence of this species in the 
palaeozoic of Victoria is of some stratigraphic importance, since 
it is apparently a widely-distributed form, having already been 
described by Barrande from the lowest bed of the Devonian 
series in Bohemia, a black limestone (FF 2 ) resting on Silurian 
Syst. Sil. Boheme, Vol. VI., Pt. I., 1SS1, Acephales, PI. I. XXV., Figs. II. 1-4. 
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