Upper Silurian. | PALAONTOLOGY OF VICTORIA. [Mollusea. 
Rare in olive mudstones of Upper Silurian (Upper Ludlow) age 
in cutting at Johnston street, Collingwood, Melbourne. In fine 
sandy Upper Silurian beds (B”) of hills in township of Whittlesea, 
parish of Toorourrong. 
EXPLANATION OF FIGURES. 
Plate LVII.—Fig. 3, fragment from Whittlesea, natural size ; (transverse undulations 
coinciding with position of septa slightly too strongly marked for the direction of the light in 
the figure). Fig. 2a, portion of strie highly magnified, showing the rarely seen transverse 
strie of growth crossing the flat spaces between the longitudinal lines. Fig. 34, entire width of 
specimen less highly magnified to show the number of the striw. Fig. 4, specimen, natural size, 
from Johnston street. Fig. 4a, portion magnified to show number of striz. Fig. 4b, portion 
more highly magnified to show the normal character of the striz and the flat interspaces. 
Pirate LVII., Fie. 5. 
ORTHOCERAS CAPILLOSUM (Baz.). 
Drscription.—Slightly compressed, section broad oval; very gradually tapering 
at the rate of 1 line in 1 inch from a diameter of 10 lines; surface girt with very 
slightly oblique, very fine, equal, rigid, thread-like transverse strie, 19 in the space 
of 2 lines at 6 lines in diameter, separated by flat spaces nearly twice the width of 
the ridges. 
A careful comparison of our fossil with specimens from the 
Upper Silurian limestone of Barrande’s Bohemian locality, Butowitz, 
near Prague, leaves no doubt of the perfect identity of our species, 
giving another proof of the correctness of the original reference I 
ventured to make of the Kilmore strata to the Wenlock period. 
The finer striz, or their greater number in a given space, readily 
distinguish the species from Portlock’s O. tenwicinctum. 
Not uncommon in the Wenlock shale of Broadhurst’s Creek 
(B° 18), E. of Kilmore. 
EXPLANATION OF FIGURES. 
‘ Plate LVIL—fFig. 5, fragment, natural size. Fig. 5a, entire width magnified to show the 
slight obliquity of the striation. Fig. 54, portion of striation more highly magnified to show 
the proportion of the narrow elevated striz to the wider flat interspaces. 
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