SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
Actinopteria cf. sowerbii, McCoy, sp. PI. V., Fig. 72. 
_ Avicula reticulata, Sowerby (non Hisinger, non Goldfuss), 
1839, in Murchison’s Silurian System, p. 614, Pl. VL., Fig. 3. 
Pterinea sowerbti, McCoy, 1852, Brit. Pal. Foss, p. 263. 
Observations.—The Victorian specimen is represented by 
an imperfect mould of the shell, and a wax impression of this 
shows it to be closely allied to the above-named species. The 
ornament of lamellated concentric folds, and the interrupted 
radii, together help to support this identification. Until better 
specimens have been discovered, however, it is safer merely to 
point out its relationship with the British fossil, which has been 
recorded as ranging from the Upper Llandovery to the Aymestry 
Limestone. 
There is another species to which our shell bears some 
resemblance, namely, “ Pterinea” lamellosa, Goldfuss,* but the 
radial ornament of the latter is much more strongly pronounced 
than in our specimen. Goldfuss’ species is a typically Devonian 
shell, and has only been doubtfully recorded from the Wenlock 
shale and limestone in Britain.t 
Horizon and Locality—Silurian (Yeringian). Reefton, 
Warburton, Upper Yarra; coll. Geol. Surv. Vict. (spec. 3431). 
(7937. | 
Actinopteria heathcotiensis, sp. nov. Pl. V., Fig. 73. 
Description.—Left valve obliquely extended to the posterior 
angle; umbo sub-anterior, rather prominent. Anterior ala ( ‘) 
small, posterior triangular, inflated in the central area; the 
longest side adjoining the posterior slope and extending half- 
way down the posterior margin. Anterior extremity narrow, 
the border curving obliquely round the ventral to the posterior 
margin, which is greatly produced, meeting the border of the 
posterior slope at a blunt angle. Posterior slope distinctly 
hollowed. Surface of shell evenly and gently convex from the 
middle of the umbonal area to the posterior corner, and more 
strongly convex from the umbo to the ventral margin. The 
shell is concentrically sulcose and striated, the striz turning up 
at an acute angle on the posterior wing. Traces of radial striz 
from the umbo to the ventral border. A salient feature of this 
species is the strongly convex ventral margin. 
Measurements.—Height, 46 mm.; length, 65 mm.; depth of 
valve, 8 mm. 
* Petrefactie Germaniz, 1837, p. 136, Pl. CXX., Figs. 1a, 6. 
+R. Etheridge, Brit. Pal. Foss., Vol. I., 1888, p. roo [recorded in error as Pterinea 
laminosa, Goldf.]. 
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