Ternary.-] PALEONTOLOGY OF VICTORIA. [Mollusca. 



the liviug Pleurotomaria Adansoniana, but the more nearly central 

 band of the P. Quoyana, and having the close sph'al threads crossed 

 by nearly equal prominent equidistant lines of growth. It differs 

 from both in its more elevated acute spire, a much smaller apical 

 angle, and more equal striae. 



From the Miocene P. Sis^nondai it differs in the whorls not 

 being angulated and in the more equal striae. From the Eocene 

 P. concava it differs in its much finer and more numerous strise. 



Rai'e in a hard pink and yellowish limestone (T" 4), like litho- 

 graphic stone, about two feet thick, interstratified with the upper 

 part of a bed of basalt, about 100 feet thick, on east bank of 

 Moorabool River, near INIaude. 



Explanation of Figures. 



Plate XXV. — Fig. I, side Tiew, natural size. Fig. \a, opposite side of same specimen, 

 showing in fractured section the character of the umbilicus. Fig. lb, portion of surface, 

 magnified, showing the decussated spiral striae and the band. 



Plate XXV., Figs 2-2J. 

 HALIOTIS OVINOIDES (McCoy). 



[Genus HALIOTIS (Linm.). (Sub.-ldngd. MoUusca. Class Gasteropoda. Order Scuti- 

 branchiata. F.am. Haliotidfe.) 



Gen. Char. — Shell ver\' much depressed, with an ovate or ear-sliaped outline formed entirely 

 of the last whorl ; spire extremely small, depressed, close to the posterior of left lateral margin ; 

 external surface usually rough, with radiating wrinkles and spiral ridges ; a sub-augulated row 

 of short tubular perforations extends from the anterior part of the outer lip close to the left 

 margin of the shell on the upper side; outer lip thin, simple; aperture extremely large, the 

 inner lip forming a flattened inflexed boundary to it ou the left side.] 



Description. — OrbicularI_y ovate, flattened above ; spire equalling in diameter 

 half the diameter of the shell in the same line, of 2 prominent whorls ; apertures 

 large, prominent, tubular; upper surface witit tiiick nearl^y straiglit radiating ridges, 

 like wrinkles, extending from the suture to within about their own distances apart 

 from the row of tubular ajiertures, each ridge most pronjinent at its outer obtusel_v 

 rounded subtubercular extremity, about 3 strong spiral ridges between the ends of 

 the radiating ridges and the tubuli ; spiral ridges of same size, but less prominent 

 between tlie ridges, and about stronger ones outside the row of tubuli. Average 

 length, H inches; comparative diameter of spire, -f^j-t't height, -fVa- ; at edge of 

 specimen 1^ incL in diameter, there are five apertures in nine lines (little more 

 than three in the same space of //. ovina at the same diameter). 



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