97 



Locality and Horizon. — Miocene, Muddy Creek, near Hamilton, 

 Victoria {Tate), 4 exs. 



Divisions of the genus Murginella have been proposed by several 

 conchologists ; these are founded chiefly upon the character presented by 

 the spire, whether eievated or hidden, whilst the outline of the shell has 

 served for further subdivision Were 1 to adopt the divisions proposed 

 by the MM. Adams, I should be necessitated to suggest others for the 

 reception of certain of the fossil forms ; not deeming this desirable, I 

 select more stable characters those of the Dlication of the columella, and 

 the absence or presence of denticles on the lip, as bases for the arrange* 

 ment of the species into artificial groups to facilitate reference, such as is 

 set forth in the folio wing conspectus. 



CONSPECTUS OF THE SPECIES OF FOSSIL MARGINELL.-E. 



I. Outer lip smooth ; columella quadriplicate. 



1. Fusiformly ovate, M. Aldingce, Tate. 



2. Ovate ventricose, M. Cassidiformis, Tate. 



3. Volutiform, M. muscurioides, Tate. 



4. Broadly ovate, M. hordeacea, Tate. 



5. Ovato-cylindrical, M. dubia, Hutton. 



6. Oval, M. albescens, Hutton. 



II. Outer lip dentate. 



A. — Columella quadriplicate. 



7. Ovate-oblong, M. Wentworthi, T. Woods. 



8. Ovate, M. strombiformis, T. Woods. 



9. Conically-ova + e, M. micula, Tate. 



10. Pyriform, M. inermis, Tate. 



11. Ovate-ventricose, M. ventricosa, Hutton. 



B. — Columella quinque-plicate. 



12. Fusiformly obloDg, M. Winteri, Tate. 



13. Oblong-cylindrical, M. propingua, Tate. 



14. Ovate-oblong, M. Woodsi, Tate. 



C. — Columella multiplicate (Section Persicula.) 



15. Columella 7-plicate, M. septemplicata, Tate. 



Remarks on the Affinities of the Species. — Of the fifteen species 

 enumerated in the foregoing table, only one is known as a living shell, 

 it is M. albescens, which inhabited the same region in Miocene times aa 

 it does now. Three have allied species among recent forms : — 



