SILURIAN BIYALVED MOLLUSCA OF VICTORIA. 
Grammysia, aff. plena , J. Hall. 
Grammysia plena, J. Hall, 1885, Pal. N.Y., Vol. V., Pt. I., 
Lamell. II., p. 382, PI. LXI., Pigs. 31, 32. 
Observations . — The antero-median area of this fossil 
exhibits the confluent character of the interrupted con- 
centric folds, also seen in the N. American species quoted above. 
The folds, moreover, become more prominent and thinner at the 
anterior end. There is also a faint, but typically placed, 
cincture, extending from the beak to the ventral margin, behind 
the middle of the anterior third. G. plena occurs in the 
Chemung and Waverley groups of Burlington, Iowa. 
Horizon and Locality . — Silurian (Melbournian). Ranges 
east of ITeathcote. An imperfect specimen in pinkish sand- 
stone. Coll. Geol. Surv. of Viet., B b 50. [7873.] 
Grammysia cuneiformis, R. Etheridge hi. 
Grammysia cuneiformis, R. Etheridge fil., 1899, Prog. 
Rep., No. XI., Geol. Surv., Viet., p. 35, PI. B., Pig. 10. 
Observation . — This species is represented in the collection 
of the National Museum by a cast of a left valve in pinkish, 
friable sandstone. 
Horizon and Locality . — Silurian (Melbournian), ITeathcote. 
Coll, by Geol. Surv. of Victoria. [7874.] 
Genus Leptodomus, McCoy, 1844. 
Jjeptodomus maccoyianus, sp. nov., PI. T., Eig. 4. 
Description.-- Valves sub-trigonal, elongate, with the hinge- 
line and ventral margin approximately parallel; anterior end 
narrow and truncated below ; ventral border sinuous, posterior 
rounded and truncated towards the cardinal line. Extremities 
of valves compressed; beaks prominent, sharp and arcuate, 
directed forward and situated sub-anteriorly. A mesial sinus 
extends obliquely from the beak to the middle of the ventral 
border; umbonal slope well-arched. Surface of valves liaviim' a 
series of closely-set, and somewhat irregular, concentric strne, 
which in some specimens are merged into concentric ridges. 
The shell -surface is also marked with faint radial strise passing 
across the ridges from the umbo to the ventral border. 
Measurements . — Type specimen: Length, 20 mm.; hem-ht 
9 mm. ; greatest depth of valve, 4.5 mm. Another specimen has ’ 
Length, 15 inm.; height, 7 mm.; greatest depth of valve, 4.5mm. 
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