Fossil Fauna, Table Cape Beds, Tasmania. 119 



preaches the anterior end of tlie mouth is more distinctly and 

 regularly convex, and as a consequence the periphery of the 

 body-whorl becomes less abruptly convexly rounded towards the 

 outer lip of the shell. 



Apical angle about sixty degrees. Whorls consisting of an 

 embryonic portion of about a whorl and a half, succeeded by six 

 I'apidly increasing very slightly convex whorls. No umbilicus. 

 Aperture oval, columella solid, arched and strongly nacreous, 

 outer lip thick internally and bevelled off to a thin outer edge. 



Spirally ornamented with strong, raised, rounded ridges, in- 

 creasing from aljout three or four posteriorly to six on the body- 

 whorl, separated from one another by a furrow about equal in 

 hreadtli to the ridges. Both ridges and furrows very linely 

 spirally striate and crossed transversely by close-set o1)lique lines 

 of growth ; at an average distance of about one millimetre the 

 lines of growth become raised into lamella?, which give rise to 

 prominent, raised, forwardly projecting scales where they cross 

 the spiral ridges. Base similarly ornamented with nine promi- 

 nent, spiral, scaly ridges, but with the scales more numerous and 

 closer together, also Ijoth ridges and furrows closely and minutely 

 spirally striate. 



Dimensions. — Type specimen, length, 28 nnn. : Ijreadth, 26 

 mm. ; height of aperture, 8-5 mm. ; breadth of aperture, 10 mm. 

 Smaller specimen, height, about 25 mm. ; breadth, 21 mm. 



Locality. — -Eocene beds of Table Cape, Tasmania. Three 

 examples. 



Observations. — This species difters from the previously described 

 species, T. etheridgei, T. Woods, from these beds, to such an 

 extent in shape, general aspect and ornament that I think it 

 superfluous to enter into any detailed dirterential characters, and 

 therefore refer to the above description in the hope that it may 

 be found suflicient for the identitication of the species. I am 

 not at present acquainted with any other living or fossil species 

 sufficiently closely related to the present fossil form to require 

 any special remarks. Specific name in compliment to Mr. E. D. 

 Atkinson, by whom it was collected from the Table Cape beds. 



81. Thalotia alternata, T. Woods. 

 T. alternata, T. W^oods, P.R.S.Tas., 1876, p. 97. 



