245 



Genus HELIACUS, D'Orbigny. 



[Moll. Cuba, t. ii. 1842, p. 68.] 



Torinia, Gray, Syn. Brit. Mus. 1840, p. 147 (list name); id. 

 1842, pp. 60, 90 (list name, not specified); vide Proc. 

 Zool. Soc. 1847, p. 151. 



This differs from Solarium principally in having rounded whorls 

 instead of being sharply keeled at the periphery ; the whorls are 

 granulated and spirally lineate ; aperture almost circular, lip 

 simple, umbilicus large. Typically the spire is much elevated, 

 and even turbinate ; but several species have a depressed spire, 

 and the shell is then planorboid. It would appear that, in 

 some cases {e.g. the living S. variegata, Gmelin) the elevation or 

 depression of the spire is only a varietal character. 



The term Torinia must fall in synonymy, as Heliacus was 

 proposed before the former was established on a firm basis, as 

 above indicated. 



Type. — Solarium helerti, Deshayes. 



Heliacus ■wannonensis, Tenison-Woods (sp.). 



1879. Solariiim ivannonensis, Tenison-Woods, Proc. Linn. Soc. N.S.W. 

 vol. iii. p. 237, pi. sxi. fig. 10. 



Shell small, discoid; spire depressed, spiral lineations granulated, 

 the largest bordering the slightly canaliculate suture ; whorls 

 rounded at the periphery, where there is a row of rather large 

 granulations ; base of the body - whorl spirally granulate, the 

 two rows having the largest granules surrounding the umbilicus, 

 which is wide and deep ; the granulations are so arranged from 

 row to row as to form broken radiating lines. 



Dimensions. — Length 3'5 mm. ; breadth 6"5 mm. 



Form, and Loc. — Eocene: Muddy Creek, Victoria. 



G. 9463. Two examples. Purchased. 



