127 



prominent ones on the periphery, crossed by about 15 faint 

 intervariceal costulations which bear bead-like granulations at 

 the intersections ; the intercostal spaces distantly transversely 

 striated. 



Varices eight, at intervals o£ about four-fifths of a whorl, 

 stout, broad, crossed by the lirag, and axially striated. 



Last whorl convex, with a rounded base contracted into a 

 short twisted beak ; ornamented same as that of the spire, ex- 

 cept that the transverse striations cut up the surface of the 

 lirse into small granulations. 



Aperture subrotund, entire ; outer lip with an acute crenu- 

 lated margin, lirate within ; inner lip reflected, smooth, with 

 an oblique fold at the front. 



Length, 13 ; breadth, 6 ; length of aperture, 4 ; of canal, 2. 



Locality. — Lower beds at Muddy Creek. 



This fossil belongs to a group typified by the recent T. Quoyi, 

 Eeeve, but it is more slender, has a larger apex, finer ornament, 

 longer canal, and a smooth inner lip. 



18. Triton Quoyi, Reeve. 



T. Quoyi, Beeve ; monograph of Triton 



This species, so common on the southern shores of Australia, 

 is known to me as a fossil by several specimens from the upper 

 beds of the Muddy Creek section 



19. Triton sexcostatus, spec. nov. Plate vi., fig. 9. 



Turriculate ; whorls nine, ending in a small obtuse apex of 

 two rounded whorls ; spire whorls convex, the earlier ones sub- 

 quadrate, ornamented with four spiral ribs, acutely nodulated 

 by the intercrossing of transverse costae, of which there are 

 six between the varices. Outer lip prominently toothed ; 

 columella with three rounded tubercles. 



Length, 21 ; breadth, 95, 



Locality. — Oyster banks at Blanche Point, Aldinga Bay. 



This fossil closely resembles T. Qitoyi, from which it is con- 

 spicuously different by its larger, fewer, and more distant 

 intervariceal costge, which number in the recent species from 

 10 to 11, whilst there are invariably six on the fossil. 



Geis'tjs Epideomus. 



synopsis of species. 

 Whorls equally attenuated in front and behind. 



Surface granulated all over by the intersections of equal 

 and equidistant lirae (12) and cost?e. 



1. E. teiiuicostatus. 



