Palaeontology oj the Older Tertiary. 323 



second, third, and fourth, fine uniform spiral threads narrower 

 than the interspaces make their appearance, on the fifth the 

 threads open out somewhat and show some finer intercalated 

 threads es)_)ecially about the median portion of the whorl, thence 

 the 'spiral sculpture tends to become obsolete, the sixth whorl 

 showinp- it more especially towards the posterior suture, thence 

 it is difficult to discern any but the merest traces of spiral 

 sculpture. The earlier whorls, especially the third and fourth, 

 show under a lens very fine, regular close-«et striae of gTO\^'th, 

 distinct in the interspaces, a few increasing in strength on the 

 fourth so as to cross the spiral threads with a slight node and 

 giving rise to a minute tesselation with three or four finer 

 striae in the interspaces, thence these stronger transverse 

 threads develop into irregular folds of growth, whilst the finer 

 transverse ornament is probably still retained to some extent 

 in the finer lines of gro^\i;h. Suture overlapping somewhat in 

 the earlier whorls, but developing to a strongly canaliculate 

 sutm-e on the body-whorl. Aperture ovate, outer lip much 

 thickened towards the posterior suture, thinning out and be- 

 coming sharp at the edge towards the canal. Columella long, 

 rapidly tapering and straight, but for a thickening at the pos- 

 terior end of the canal, in young- specimens there are two slight 

 undulations in the length of the columella, canal long and nai*- 

 row. 



Dimensions. — Length of a nearly complete adult specimen, 200 

 mm. ; estiinated length perfect, 215 mm. ; breadth, 80 mm. ; 

 length of aperture, 65 mm. ; breadth of aperture, 33 mm. ; 

 length of aperture and canal, 133 mm. A young specimen of 

 five whorls gives, length, 65 mm. ; breadth, 17 mm. ; length 

 of aperture, 13 mm. ; breadth of aperture, 7 mm. ; length of 

 aperture and canal, 45 mm.. 



Locality. — Lower Beds of Muddy Creek sections near Hamil- 

 ton, Western Victoria. — Balcombian. — Eocene. 



This species is also represented in the National Museum Col- 

 lection, Melbourne, by some specimens preserved in gypsum from 

 the River Murray Cliffs. 



Observations. — This is another very fine example of the genu's 

 Clavella, and is specifically distinct from C. bulbodes, Tate. 

 The present species, though of something like the same propor- 



21A 



