ON AN UNNAMED SPECIES OF PECTEN FROM THE 
TERTIARY (BARWONIAN) OF SOUTHERN AUSTRALIA. 
By Frederick Chapman, A.L.S., F.R.M.S., Palaeontologist to the 
National Museum, Melbourne. 
(Plate V.) 
A form of Pecten, somewhat closely related to Tate’s Pecten 
consobrinus has long been known to Australian palaeontologists as 
P. consobrinus var. In Professor Tate’s “ A Revision of the Older 
Tertiary Mollusca of Australia,”* * that author refers to P. consobrinus, 
var., as occurring at Aldinga Bay (Lower beds), Shelford, Maude and 
Belmont, Waurn Ponds, and Spring Creek. Messrs. Dennant and 
Kitson, in their “ Catalogue of the Described Species of Fossils (except 
Bryozoa and Foraminifera) in the Cainozoic Fauna of Victoria, 
South Australia, and Tasmania, ”f cite the following localities for 
Pecten consobrinus var. Tate Aldinga (Lower beds), Aire Coast, 
Fishing Point and Guerard Hill, Shelford, Lower Moorabool, Maude, 
? Corio Bay, Curlewis-Belmont, ? Mitchell River, Waurn Ponds, 
and Spring Creek. 
It will thus be seen that this particular form is practically re- 
stricted to Janjukian beds, and possibly to the horizon immediately 
below, or the summit of the Balcombian series. 
The species P. consobrinus was originally described from the 
Upper beds at Aldinga ; whilst the variety occurs in the lower part 
of the same series, which is shown by its faunal characters, allowing 
for local lithological differences, to belong to our Victorian Jan- 
jukian beds. 
The present note is written to establish a name for this variety of 
P. consobrinus, for the convenience of future reference. Since it 
would appear illogical to refer to an ancestral form of an already 
described species as a variety thereof, it seems advisable to give it 
a specific standing, at the same time bearing in mind the fairly close 
relationship existing between it and the species from the younger 
beds. Its claims to a specific name are perhaps as great as are those 
of P. antiaustralis and P. australis. The affinity with P. consobrina 
is denoted by the denomination praecursor. 
Description of Type of Pecten praecursor, sp. nov. 
( = “ P- consobrinus var.” Tate). 
The type selected is a left valve of medium size (between the 
neanic and ephebic stages). 
Locality— Spring Creek, Torquay (ex Dennant Coll.) 
* Trans. R. Soo. South Australia, vol. xxiii, 1899, p. 269 
f Rec. Geol. Surv., Victoria, vol. i., pt. 2, 1903, p’. 119 . 
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