SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
there is an obtuse shoulder, and from thence the surface slopes 
rapidly away to the posterior margin. The presence of the 
posterior shoulder and the moderately prominent beaks preclude 
this form from being referred to the genus Cardiomorpha, to 
which it other wise bears some resemblance. The valves are 
concentrically striated or finely sulcate, and the character of 
these surface markings is closely comparable with that seen in 
the smaller species of Grammy sia described from the Hamilton 
Group of North America. 
Measurements. 
Approximate length, 28 mm. 
Height, 12 mm. 
Thickness (before crushing), probably about 8 mm. 
Observations. — The fossil recorded as ? Cypricardia retusa, 
Sower by,* of the Upper Ludlow series of Delbury, near Ludlow, 
bears a striking resemblance to our species, with the 
difference, however, that in the latter the beaks are situated 
farther forward, and the postero-umbonal slope has an accen- 
tuated shoulder. Another somewhat allied form is Grammysia 
ulrichi, Clarke, t from the Devonian of Brazil. 
Horizon and Locality . — Silurian (Melbournian), Yarra Im- 
provements, S. Yarra. Lresented by Mr. L. Spry. [7871.] A 
somewhat similar form to the above occurs in the Silurian 
(i'eringian) calcareous shales at Griffith’s Kiln, seven miles 
south of Mansfield. Specimen presented by Mr. E. 0. Thiele. 
[1573.] 
Grammysia, cf. arcuata, Conrad, sp. 
Posidoniaf arcuata, Conrad, 1841, Geol. Surv., N. York, 
Ann. Rep, p. 53. 
Grammysia arcuata, Conrad, sp., J. Hall, 1885, Pal. N.Y., 
Vol. V., Pt. I., Lamell. II., p. 373, PI. LXL, Pigs. 1-9; PI. 
LXIII., Fig. 6 ?; PI. XCIII., Fig. 27. 
Observations. — This is an imperfect specimen of a Gram- 
mysia in olive mudstone; only the anterior half of the valve 
being preserved. The character of the sharp, concentric folds 
reminds one of G. arcuata, Conrad sp., of the Hamilton Group 
of N. America. 
Horizon and Locality. — Silurian (Yeringian). Wilson’s, 
near Lilydale, Victoria. Presented by Mr. J. T. Jutson. [7872.] 
* Sowerby in Murchison’s Silurian System. Pt. II., 1839, p. 609, PI. V., Fig. 3. (Now 
referred by some English palaeontologists to Orthonota, and included with C. amygdalina, 
Sow. sp. 
•j- See Katzer, Grundzuge der Geologie des Amazonasgebietes, 1903, p. 207, Pl. XIV., 
Fig. 19. 
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