Tertiary.] PALAEONTOLOGY OF VICTORIA. \_Mallusca. 



nearly horizontal, and about half as wide as the space between the two rows ; both 

 spaces marked only by the coarse lines of g-rowth. Whorls anterior to the tubercles 

 crossed by deep narrow spiral sulci, having flat spaces between them about equal 

 to half the distance of the longitudinal ribs from each other, usually about 3 

 of these spiral strioe visible on each of the whorls of the spire, crossing- the 

 longitudinal ridges. Pillar folds slender, widely sajjarated oblique, 3 or 4 ; the 3rd 

 or 4th when it exists, posterior, abruptly smaller than the 2 anterior plaits. Outer 

 lip thin, smooth. Length of large specimen, 2 inches; proportional length of body 

 whorl, ^y^j; penultimate whorl, i^%; greatest width, JJ^y to -j^Sy. Specimen 8 lines 

 long gives all the same proportional measurements. 



A careful comparison of specimens of the true Volutilites scalaris 

 (Sow. sp.), fi'om the midille Eocene beds of the Isle of Wight and 

 Barton, wall show (what none of the existing figures or descriptions 

 would) that our species, which I have named Valuta anti-sea laris, 

 is not identical, but a most remarkable instance of a representative 

 form, distinguished with apparent doubt perhaps by a slightly 

 longer spu'e, less ventricose body, and the ribs less twisted at their 

 anterior end, but with perfect certainty, by the spire, which in the 

 European species is sharply pointed (in accordance mth the genus 

 Volutilites, Swain.), and of 8 or 9 gradually and regularly tapering 

 whorls, the apical 2 or 3 smooth, while in the Victorian species it 

 terminates in an obtusely rounded smooth swollen nucleus or 

 "pullus" of 1^ tui'ns, below which are only 5 sculptured whorls in 

 adult individuals. 



In accordance with the slightly more slender form, the pillar is 

 less curved than in the English species, and the plaits slightly 

 thinner and more oblique ; the number of ribs in a whorl is greater, 

 beuig about 14 or 15 in the English species, but in all other 

 characters the coincidence or representation of characters is so 

 complete that, if the tip of the spire were in each case absent, the 

 nicest eye could scarce separate them ; yet the cUstinguishing 

 character is one of such importance, and so invariable, that there 

 can be no doubt of its marking a perfectly distinct species. 



This species is also closely allied to the V. nodosa (Sow.) of 

 the Hampshire Eocene Tertiary, Barton clay, and Bracklesham 

 beds, but may be distinguished by the upper row of tubercles of the 

 spiral whorls being distinctly separated from the suture by a space 

 equalling about half the width of the space between the upper and 

 lower rows of tubercles on each whorl as V. scalaris is. 



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