ART. 20 THE GENUS SIPHOISTIISrA AND OTHER GENERA CUSHMAN 9 



depressed; wall very coarsely perforate, peripheral carina also 

 coarsely marked; aperture broadly elliptical with a very distinct 

 thickened lip and prominent neck. 



Diameter 0.50 mm. ; thickness 0.22 mm. 



Holotype. — (Ciishman Coll. 6588) from the Balcombian, Lower 

 Beds of Muddy Creek, Victoria, Australia, collected by W. J. Parr. 

 I have material also from the Janjukian Miocene, green marls. Bird 

 Eock Cliffs, Torquay, Victoria, Australia, collected by W. J. Parr 

 and from the Miocene of the Filter Quarry, Batesford, near Geelong, 

 Victoria, Australia, collected by A. C. Collins. 



This is evidently the species recorded by Chapman and others 

 from the Miocene of the Australian region. Like many other species 

 of the Australian Tertiary and living Indo-Pacific forms, it shows 

 close relationships with our Oligocene and Miocene species such as 

 8. advena and S. pulchra. It is perhaps nearer to S. reticulata than 

 any other of the species described. 



Specimens from the Oligocene of Clifton Bank, near Hamilton, 

 Victoria, Australia, also appear to belong here. 



SPECIES FROM THE PLIOCENE 

 SIPHONINA TUBERCULATA (A. Silvestri) 



Plate 3, figs. 1 a-c 



Truncatulimi reticulata (Czjzeiv), var, tuherciilata A. Silvestki, Mem. Pont. 

 Accad. Nuovi Lincei, vol. 15, 1898, p. 300, pi. 6, figa. 11 Or-c. 



Test only slightly compressed, nearly equally biconvex, periphery 

 acute, with a distinct, fimbriate carina; chambers indistinct due to 

 the surface ornamentation which consists of numerous rather large 

 tubercles in general following the lines of the sutures ; aperture with 

 a distinctly developed neck and slight lip. 



Diameter 0.45 mm. ; thickness 0.27 mm. 



The types of this species are from the Pliocene about Siena, Italy. 

 It is a distinct species. 



SIPHONINA PLANOCONVEXA (A. Silvestri) 



Plate 3, figs. 2 a-c 



TruncatuUna retici'lata (Czjzek), var. planoconvex a A.. Silvestbi, Mem. Pont. 

 Accad. Nuovi Lincei, vol. 15, 1898, p. 300, pi. 6, figs. 12 a-c. 



Test plano-convex, dorsal side flattened, ventral side strongly 

 convex, periphery acutely angled, with a sharp peripheral carina; 

 chambers with about five making up the last-formed coil, inflated 

 on the ventral side ; sutures of the dorsal side flush with the surface, 

 marked by the fimbriate keels of the chambers, on the ventral side 



