In Papua a _Pecten_ (_P. novaeguineae_) has been recorded from the ? Lower Pliocene of Yule Island. =Kalimnan Bivalves.--= The Kalimnan beds contain the following restricted or upward ranging species:--_Ostrea arenicola_, _O. manubriata_ (Fig. 96 D), _Pecten antiaustralis_ (also in the Werrikooian Series), _Perna percrassa_, _Mytilus hamiltonensis_, _Glycimeris halli_, _Limopsis beaumariensis_ (also Werrikooian) (Fig. 96 E), _Leda crassa_ (also living), _Trigonia howitti_, _Cardita solida_, _C. calva_ (also living), _Erycina micans_, _Meretrix paucirugata_, _Sunetta gibberula_, _Venus (Chione) subroborata_ (Fig. 96 F), _Donax depressa_, _Corbula scaphoides_ (also living), _Barnea tiara_, _Lucina affinis_, _Tellina albinelloides_ and _Myodora corrugata_. =Werrikooian Bivalves.--= The next stage, the Werrikooian (Upper Pliocene), contains a large percentage of living species, as _Ostrea angasi_, _Placunanomia ione_ (ranging down into Janjukian), _Glycimeris radians_, _Leda crassa_ (also a common Kalimnan fossil), various species of _Venus (Chione)_, as _V. strigosa_ and _V. placida_, and _Barnea australasiae_. =Pleistocene Bivalves.--= The bivalved shells of the Pleistocene are similar to those now found living round the Australian coast, as _Pecten asperrimus_, _Mytilus latus_, _Leda crassa_, _Soletellina biradiata_ and _Spisula parva_. Pleistocene shells of bivalved genera occur in the coastal hills of Papua, including the following:--_Cultellus_, _Corbula_, _Mactra_, _Tellina_, _Venus (Chione)_, _Dione_, _Dosinea_, _Leda_ and _Arca_. The _SCAPHOPODS_ ("digger foot") or the "Elephant-tusk shells" are adapted, by their well-developed foot, to burrow into the mud and sand. [Illustration: =Fig. 97--FOSSIL SCAPHOPODS and CHITONS.= A--Dentalium huttoni, Bather. Jurassic. New Zealand B--Dentalium mantelli, Zittel. Cainozoic. Victoria C--Chelodes calceoloides, Eth. fil. Silurian. New South Wales D--Ischnochiton granulosus, Ashby and Torr sp. Cainozoic (Balc). Victoria E--Cryptoplax pritchardi, Hall. Cainozoic (Kalimnan). Victoria ] =Devonian Scaphopods.--= This group of mollusca makes its first appearance in Australasian sediments in the Middle Devonian (Murrumbidgee beds) of New South Wales, represented by _Dentalium tenuissimum_. =Jurassic Scaphopods.--= In the Jurassic strata of the Mataura Series of New Zealand, _Dentalium huttoni_ (Fig. 97 A) occurs at the Kowhai River and Wilberforce. =Cretaceous Scaphopods.--= _Dentalium wollumbillensis_ occurs in the drab and dark-coloured limestones of the Lower Cretaceous of the Lake Eyre Basin in S. Australia, and the same species is also found in the Lower Cretaceous (Rolling Downs Formation) of Wollumbilla, Queensland. =Cainozoic Scaphopods.--=