29 
Pigure 4, of liis Monograph of Silurian Brachiopoda ; the surface is almost 
smooth, and the front very elevated, otherwise the species is so w^ell-knowm 
that it is unnecessary to say more about its characteristics. 
Horizon and Localities .- — This is one of the most common species in the 
Upper Silurian of England and Sweden. In Australia it has been collected 
in a shaley limestone at Slaughta [Slaughter] House Creek, Delegate Pwiver. 
Division — MOLLUSC A. 
LAMELLIBSANCHIATA. 
Genus — PTERINEA, Goldfuss. 
1. Ptehinea ampliata, J. Fhillips. 
udvicula ampliata. J. Phillips, 1858, Mem. G-eol. Survey Gt. Britain, I, Part i, p. 367, pi. 23, 
fig. 1. 
The shape of the shell is obliquely suboval, the posterior end a little 
prolonged and slightly sloped; the lower margin is suhsemicircular, and forms 
a fairly regular curve that extends from the extremity of the posterior side to 
the anterior ear. The two valves were close to one another, and very thin ; 
the impression of the right valve, the only one known to me, shows traces of 
very fine growth lines, which are the only ornaments with which the surface 
was furnished. The scar of the adductor muscle is very eccentric, moderately 
large, rounded, and situated on the posterior prolongation of the shell about 
one centimetre from the margin. 
Delations and Differences . — In the ornamentation of the surface it 
approaches P. retrojlexa, Wahl., but differs from it in the elongated shape 
and thinness of the shell. 
Dimensions. — Length, four and a half centimetres; breadth, about 
five centimetres. 
Horizon and Localities . — The impression of this species being associated 
with Cromus holiemicus, Barrande, and Atrypa ? hemispherica, Sowerby, it 
must necessarily come from Silurian beds of the same age as the Llandovery. 
It has been found at Dangelong, in the Cooma District. J. Phillips collected 
it in a purple lamellar sandstone of Upper Silurian age at Trichrug Hill, 
Llangadog. 
