MABGINELLA. 88 



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



6. 4213. A series exhibiting stages of growth. 



Presented hy John Dennant, Esq. 



G. 9341. Several specimens of the adult stage. Purchased. 



Marginella muscarioides, Tate. 



1878. Marginella muscarioides, Tate, Trans. Phil. Soc. Adelaide, 1877-8, 



p. 91. 

 1889. Marf/inella muscar aides, Dennant, Trans. Roy. Soc. South Aiist. 



vol. xi. p. 43. 



This species is characterized by its broad aperture, which opens 

 out anteriorly and is deeply channelled ; the body-whorl is gibbose, 

 and well-preserved specimens exhibit inconspicuous, narrow, longi- 

 tudinal bands of brownish tint. 



It differs from M. wentworthi in the characters above noted, as 

 well as by the absence of crenulations on the outer margin. The 

 latter in M. muscarioides is much thickened, especially towards 

 the middle, where an obscure denticle is observable in some 

 specimens ; the inner margin is somewhat callous, and carries 

 lour conspicuous plications. Professor Tate remarks that in a 

 broad sense this species is a diminutive M. muscaria, Lamarck, 

 from which, however, it differs, amongst other things, in that the 

 callous outer margin of the latter species is extended "on to 

 the penultimate whorl, thence spreading over the base of the 

 shell, and giving rise to a flattened appearance varicosely margined 

 on the left side." The sutural region in M. muscarioides is 

 somewhat depressed. 



Mr. Dennant quotes this species as occurring in the younger 

 beds at Muddy Creek. 



Pimensions. — Length 7"5 mm. ; breadth -i'S mm. ; length of 

 aperture 5 mm. 



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



G. 4212. Several specimens. Presented hj John Pennant, Esq. 

 G. 9338. Examples illustrating stages of growth. Purchased. 



