SILURIAN BIYALYED MOLLUSCA OF VICTORIA. 
forward and inward, umbonal area triangular, with a slight 
vertical depression from the beak towards the ventral margin. 
Cardinal line long and straight; cardinal area compressed in 
front and behind. Surface marked with fine concentric lines of 
growth, which become lamellose in the cardinal area. 
Measurements. — Length, 16 mm.; height, 14 mm.; depth 
of valve, 3.5 mm. 
Observations. — This species is referred to the genus 
P aralleloclon with some reservation, since the hinge structure is 
obscure. The evidence tends, however, in the direction of this 
genus, for the beaks are not closely adpressed, and the cardinal 
area is lamellose, as in typical forms of P aralleloclon, pointing 
to the former presence of an external and amphicletic ligament. 
The specimen figured on PI. VI., Fig. 4, although at first 
suggestive of T ellinoysis, is apparently referable to this species, 
possessing the lamellose cardinal area and traces of teeth. 
Horizon and Locality. — Silurian (Melbournian). Coll, of 
the Geol. Surv. Viet, in the Nat. Museum; Police paddock, Kil- 
more, B b - 22. Also a doubtful example from Swanston-street 
sewer, Melbourne. [7925 (type), 7926.] 
Family Pterineidse. 
Genus Pterinea, Goldfuss, 1832. 
Pterinea linecita, Goldfuss. PI. IV., Fig. 60. 
Pterinea lineatci, Goldfuss, 183 7, Petrefactim Germanise 
Vol. II., p. 135, PI. CXIX, Figs. 6 a-c. 
cf. Ambony chia tatei, Cresswell, 1893, Proc. Rov Soc 
Viet., Vol. V., N.S., p. 44, PL IX., Fig. 8. 
Observations.— There is very little doubt that the imperfect 
valve figured under the name of Ambony chia tatei by the Rev 
A. W. Cresswell is an example of Pterinea lineata, Goldfuss^ 
Fragments of the above form are fairly common at some 
Yermgian localities east of Melbourne, and it seems to be a 
characteristic form in the uppermost Silurian beds in Victoria 
In Britain, this species was recorded by McCoy from the 
Ludlow beds , in Germany it is r, well-known Devoni&n fossil 
Horizon and Locality.— Silurian (Yeringian) ? Lilvdalp 
(Rev. A. W. Cresswell); north of Lilydale, in mudstone ore 
sented by the Rev. A. W. Cresswell ; and Croydon near Lilvdale 
m mudstone, presented by Mr. Thos. Warn [7927, 2269 (type 
of tatei )]. 
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