SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
The original is an impression of a left valve in blue mud- 
stone, and the drawing has been made from a well-defined cast 
in Wax. 
Observations.—The above fossil is a typical A viculopecten, 
in accordance with the emended definition of the genus given by 
J. Hall,* since it has a short hinge-line and well-defined ears. 
Horizon and Locality—Silurian (Melbournian). Yarra 
Improvement Works, 8. Yarra; presented by Mr. F. P. Spry. 
(7940. | 
Family Modiolopside. 
Genus Moprouopsis, J. Hall, 1847. 
Modiolopsis melbournensis, sp. nov., Pl. V., Figs. 76, 76a. 
Description—Shell small, sub-quadrate, elongate, com- 
pressed posteriorly; length rather less than twice the height. 
Cardinal line nearly straight; ventral margin parallel. 
Anterior extremity narrowly rounded, and inecurved under the 
prominent sub-anterior beaks. Posterior extremity broadly 
rounded, and meeting the hinge-line at an obtuse angle. 
Umbonal ridge extending from the beaks to near the postero- 
ventral angle. Greatest convexity of surface in the umbonal 
region; ventral area somewhat depressed. Surface marked by 
fine, irregularly concentric growth-lines. 
Measurements—Length, 16 mm.; height, 9 mm. 
A ffinities.—A form nearly allied to the above is Modiolopsis 
solenoides, Sowerby, sp.t, from the Upper Ludlow, near Bridge- 
north, England. It differs from our species, however, in its 
greater compression, less prominent beaks, and in having a 
broad median depression in the ventral region. 
Horizon and Locality.—Silurian (Melbournian). Yarra 
Improvement Works, 8. Yarra. [7941.] 
Modiolopsis complanata, Sowerby, sp. Pl. V., Fig. 77. 
Pullastra complanata, Sowerby, 1839, in Murchison’s 
Silurian System, p. 609, Pl. V., Fig. 7. 
Modiolopsis complanata, Sow. sp., McCoy, 1852, Brit. Pal. 
Foss., p. 266. 
* Pal. N. York, Vol. V., Pt. I., 1884, Lamell. I., p. XII. 
+ Siluria, 3rd ed., 1859, Pl. 23, Fig. 9 [‘‘ Orthonota (?Cypricardia) solencides”’). 
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