SILURIAN BIVALVED MOLLUSCA OF VICTORIA. 
Horizon and Locality—Silurian (Yeringian). The figured 
specimen is from the mudstone N. of Lilydale; the large example 
is from the limestone of Cave Hill, Lilydale. Both specimens 
were collected by the Rev. A. W. Cresswell, M.A. [2264, 2270. | 
Actinopteria boydi, Conrad sp., Plate 1V., Fig. 69, Pl. V., 70. 
Avicula boydii, Conrad, 1842, Journ. Acad. Nat. Sci., 
Philad., Vol: VIII., p. 237, Pl. XII., Fig. 4. 
Pterinea boydi, Conrad sp., McCoy, 1852, Brit. Pal. Foss., 
p. 259. 
Actinopteria boydi, Conrad sp., J. Hall, 1884, Pal., N. 
York, Vol. V., Pt. I., Lamell. I., p. 113, Pl. XIX., Figs. 2-24; 
Pl. LXXXIV., Figs. 16, 17. 
Observations—This very handsome species, although 
variable, is sufficiently distinguished by its characteristic radial 
and concentric ornament; the concentric laminz are undulose 
and concave between the rays, meeting the latter in a more or 
less sharp point. The edges of the concentric lamelle are often 
so pronounced as to give rise to a series of scalloped frills. The 
areas cut off by the concentric lamelle are usually much higher 
than broad. 
This species occurs in the Upper Ludlow in Britain, at 
Kendal, in Westmoreland. In N. America it is abundant in 
the shales of the Hamilton Group in New York State. 
Horizon and Locality—Silurian (Yeringian). In mud- 
stone from Wilson’s, near Lilydale, presented by Mr. J. T. 
Jutson. Also from a shallow well at Croydon, presented by 
Mr. Thos. Warr. — ['7933-35.] 
Actinopteria asperula, McCoy sp., var. eroydonensis, nov., 
Plate V., Fig. 71. 
Observations.—This variety is distinguished from the type 
species described by McCoy,* by its shorter form and fewer 
ribs, the latter numbering about 22 on the body of the shell in 
the Victorian variety. The essential characters of our shell, so 
far as they can be made out, are, with the above exceptions, the 
same as those of the specific form. McCoy’s species was 
recorded from the Caradoc series of Radnorshire, Wales. 
Horizon and Locality—Silurian (Yeringian). In the yel- 
low mudstone from a shallow well near Kilsyth Post Office, 
Croydon, near Lilydale. Presented by Mr. Thos. Warr. [7936. | 
* Plerinea? asperula, Ann. Mag. Nat. Hist., 2nd ser., Vol. VII.. 1851, p. 60. Brit. 
Pal. Foss., Pt. II., 1852, p. 250. Pl. II., Fig 5. 
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