29 



This species differs from C. ligatus in being more elongate, 

 ■whilst it is minus the rim-like keel of that species, and the 

 lineatious on the whorls of the spire are not conspicuous. The 

 staging of the whorls is a peculiar feature ; when in the brephic 

 and neanic periods of growth there is little or no attempt at 

 staging, but in the adult, and especially in senile forms, the 

 anterior whorls drop very sharply. It is highly probable that 

 this catabatic phenomenon is the precursor of the establishment 

 of an elevated spire in its descendants ; but that is a point 

 which cannot be definitely settled until the phylogeny of the 

 Gasteropoda has been worked out. 



Dimensions.— \iGii^th 31 mm. ; breadth 15 mm. 



Form, and Loc. — Eocene : Victoria. 



48052. A series of ten specimens ranging from the neauic 

 to the catabatic stages ; fi'om Schnapper Point. Furchased. 



70423. Four specimens ; from Meribee Plains. Furchased. 



Conus (Leptoconus) ne^wtoiii, sp. nov. 



[Plate II. Figs. ?,(i-d.'] 



Protoconch small, composed of two and a half smooth turns, 

 indistinctly striated with growth -lines anteriorly ; posterior portion 

 slightly oblique with reference to the axis of the shell. 



Spire elevated, acute, convex, about one- sixth the total length 

 of the shell ; spire-whorls seven in number, staged, excavated, 

 spiral lineatious bold and continuous, growth-lines prominent, 

 sinuated. Keel sharp and plain, not being crenulated even in 

 the brephic stage. Body-whorl elongate, ornamented throughout 

 its length by distant spiral sulcations which are punctated where 

 crossed by the lines of growth. Aperture long and narrow ; outer 

 margin thin and arched ; posterior sinus very deep ; anteriorly 

 the aperture is somewhat dilated and the columella is slightly 

 twisted. 



The elongation and narrowness of the body-whorl are dis- 

 tinctive features. Its nearest ally in the Australian Tertiaries 

 is C. extenuatus, Tate, which, however, is broader, whilst its 

 body-whorl is not so long, its periphery is not so sharply keeled, 

 the earlier whorls are crenulated, and the ornamentation of the 

 spire differs. C. newtoni closely resembles C. sieholdi, Reeve, 



