216 STKOMBUS. 



Erato pyrulata, Tate. 



1890. Erato pyrulata, Tate, Trans. Eoy. Soc. South Aust. vol. xiii. pt. 2, 



p. 216. 

 1892. Erato pyruMa, Tate, id. vol. xiii. supp. pi. xiii. figs. 12, 12a. 

 1895. Erato pyrulata, Tate and Dennant, id. vol. xix. pt. 1, p. 111. 



This species is characterized by its columella ending anteriorly 

 in a strong spiral plait, in having a moderately wide aperture, 

 and by the thickening of the outer margin being squarely 

 shouldered behind. In shape it is globose-pyriform, and the 

 spire in the adult is so short that it does not rise above the level 

 of the curved posterior notch of the aperture. 



As Professor Tate remarks {op. supra cit.), its "terminal spiral 

 plait on the columella, running out to form the left margin of 

 a slightly efEuse canal," is not characteristic of the genus. "The 

 denticles on the two margins appear when the adult stage is 

 reached, but the columella-plait belongs to all ages." Compared 

 with Marginella edentula, Tate, it is less inflated, and has not 

 such a convex columella. 



Dimetismis. — Length 6-5 mm. ; breadth 4-5 mm. 



Form, and Loc. — Eocene : Aldinga, South Australia. 



G. 9474. Examples illustrating stages of growth. Purchased. 



Family STROMBID^. 



Genus STROMBUS, Linnteus. 

 [Syst. Nat. ed. 10, 1758, p. 742.] 



Shell ovoid, tuberculose or spinose, solid ; spire with several 

 whorls; aperture elongate, obliquely truncated and channelled 

 anteriorly, canaliculate posteriorly ; outer margin dilated, usually 

 thick, often produced behind, sinuate and sometimes channelled in 

 front ; columellar border simple, enamelled. 



The following species is selected by Lamarck h — 



Ti/pe. — S trombus pugilis, Linnaeus. 



> Mem. Soc. Hist. Nat. Paris, 1799, p. 72. 



