Tertiary.} PALEONTOLOGY OF VICTORIA. [Mollu-sca. 



becoming obsolete at about half the length of the body whorl (sometimes shorter 

 and often somewhat longer), but becoming very prominent, and separated by rather 

 wider deep concave spaces on the shoulder, where each terminates in an obtusely 

 rounded end at the constriction or sub-sutural groove, above which each rib seems 

 continued as a blunt conoidal tubercle, above which moniliform rows of tubercles, 

 a narrow step-like undulated flattened or slightly concave space extends to the 

 suture, perpendicular to the axis. Lower or anterior half of body whorl strongly 

 marked with transverse or obliquely spiral deep narrow sulci, having broader 

 flattened spaces between them, occasionally extending, more faintly marked, a 

 further variable distance towards the suture. Mouth, with a slight posterior 

 channel, oblong, narrowed in front ; outer lip smooth within (edge sometimes very 

 faintly crenulated in old individuals); inner lip slightly curved, with 4 slender 

 oblique nearly equal plaits about the middle, the anterior slightly larger than the 

 posterior ; occasionally traces of a very small 5th plait occur. Usual length, 1 inch 

 9 lines ; proportional length of body whorl, -^j^% to ^%% ; penultimate whorl, -^^\ to 

 tVc) width, ,^5°^ to yV^. Young, 6 lines long; body whorl, -^^ij; penultimate whorl, 

 TTnyJ width, -5-%% ; at this size only 3 sculptured whorls and the pullus ; 22 ribs on 

 body whorl. Some specimens show that the mouth was dark-violet within. 



From the examination of a great number of specimens from the 

 Lower Miocene or " Tongrien " beds of Lattorf, near Bernberg, I 

 long ago satisfied myself that the V. suturalis and V. cingulata of 

 Nyst were only extreme varieties of one species, and Beyrich 

 seems somewhat inclined to the same opinion, from examination 

 of a larger number of specimens from other localities, of one of the 

 varieties at least, than Nyst seems to have had of either, as he 

 marks them both as rare in his " Coquilles et Polypiers Fossiles de 

 Belgique ; " and the latter name would be the best to retain, as it 

 indicates the remarkable girding of the whorls by the deep sulcus 

 or constriction which seems to cut off a sub-sutural row of tubercles 

 from the ends of the longitudinal ribs in the most common variety ; 

 still, as in the V. bulbula (Lam.), to which Nyst likens his 

 V. suturalis^ specimens may be found sho-ftiug all the passages 

 between the most strongly marked sub-sutural sulcus and its entire 

 absence ; the latter variety I mark ft indivisa, and in it the ribs are 

 often fewer and more sigmoid, and the shell narrower, than in the 

 ordinary forms, though none of these characters are constant ; in 

 this variety the spiral striae are often confined to the anterior base 

 of the shell, leaving the body whorl and ribs smooth and polished. 

 Var. a persulcata has the ribs rather more numerous and straighter 

 than the ordinary type, and the spiral sti'ise very strongly marked 

 over the whole body whorl and spire, so as to be in this respect 

 intermediate between the Hampshire Barton clay V. amhigua and 



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