l^ictoruin Fossils, Part XVII. .S5:^ 



France, Malta and Italy, although recorded, apparently in error, 

 from the Lower Eocene, since no Eocene locality is given in the list 

 tliat follows. The Australian species on the other hand, has a very 

 extensive range, from Oligocene to Lower Pliocene, and throughout 

 seems to maintain its specific characters. 



Oligocene or Balcombian. — Muddy Creek, near Hamilton (lower 

 beds), Newport and Altona bores. Port Phillip. Balcombe Bay 

 and Grice's Creek, Port Phillip. 



Miocene or Janjukian. — Gellibrand River (low down in series). 

 Brown's Creek, Otway Coast. Birregurra. Lower Moorabool, Mit- 

 chell River, Gippsland. Mount Gambler, South Australia. Table 

 Cape. Tasmania. Spring Creek, near Torquay. Flemington, near 

 Melbourne. 



Lower Pliocene or-Kalimnan. — Beaumaris. 



Fani. N AUTILIDAH, Owen. 



Genus Nautilus, Linne. 



Xautilus balcojnbenais, s}). nov. (Plate IIL, Fij;s. 3, 4; Plate IV. 

 Figs. 5, 6; Plate VIIL, Figs. 18, 19). 



Description. — Shell well inflated, periphery well rounded. Dor- 

 sal arch not so deep as in N. geelongensis . Septa, about 17 in the 

 last Avhorl; sutures slightly waved. Umbilicus narrow and deep. 

 Siphuncle a little above the centre in a young specimen. Young 

 examples show a striated surface of shell, as in adult forms from 

 mesozoic strata. 



Dlmt)isions. — Type specimen (from Balcombe Bay) : greatest 

 diameter, 205 mm.; height of apei'ture, 118 mm.; width, 110 mm. 

 Another specimen (from Muddy Creek) : greatest diameter, 80 

 mm. ; height of aperture, 45.5 mm. ; width, 42 mm. A small speci- 

 men (from Balcombe Bay) : Height of aperture, 23 mm. ; width, 

 26 mm. 



Affinities. — This Nautilus attains to a large size, but is very 

 difficult to secure in anything like a complete state owing to the 

 thinness of the shell, and its frequent occurrence in loose, shelly 

 marl. The type of shell is near N . regalis, Sowerby,! but, unlike 

 that species, has an open, though narrow umbilicus. At first sight 

 it might be confused with N . geelongensis, as a compressed variety, 

 but the latter species has fewer chambers, a more strongly arched 

 dorsum, and a siphuncle situated slightly below the centre. The 



1 Mineral Concholotfi , 1SS2, vol. 



