282 



Genus ETHALIA, Adams. 

 [Proc. Zool. Soc. 1853, p. 189.] 



"Shell orbicular, turbinately depressed; whorls convex, smooth,] 

 or trausversely striated, the last rounded at the periphery;! 

 umbilicus partly [or almost entirely] closed by a callous deposit ;| 

 columellar lip endiug anteriorly iu an obtuse dilated callus." — -i 

 PiUhry. 



The restriction of this genus, as proposed by Mr. Pilsbry,' is I 

 here adopted. 



Tyjje. — TImhonium g immense, Quoy and Gaimard. 



Ethalia zelandica, 



1853. JJmbonium zelandicum, A. Adams, Proc. Zool. Soc, p. 189. 



1854. Rotella zelandica, Hombron and Jacquinot, Voy. au Pole Sud, Zool. 



t. V. p. 53, pi. xiv. figs. 5, 6. 

 1873. Rotella zelandica, Yon Martens, list Moll. N.Z. p. 34. 

 1873. Rotella zealandica, Hutton, Cat. Marine Moll. N.Z. p. 35. 

 1873. Rotella zealandica, Hutton, Cat. Tert. Moll. N.Z. p. 35. 

 1880. Rotella zealandica, Hutton, Man. N.Z. Moll. p. 92. 

 1890. Ethalia zelandica, Pilsbry, Tryon's Manual of Conchology, vol. xiJ 



p. 459, pi. Iviii. figs. 9, 32, 33 ; pi. lix. fig. 66. 

 1895. Rotella neozelanica, Hutton, Linn. Soc. N.S.'W., Macleay Mem. Vol.] 



p. 68. 



Shell nacreous, orbicular, depressed ; last whorl subangulate 

 at the periphery, suture linear, growth-lines conspicuous, spiral 

 striae obsolete in fossil examples, except on the base ; umbilicus 

 suiTounded by a free, undulating area circumscribed by an 

 irregular lineation, almost entirely filled with callus ; inner 

 margin of the aperture profoundly excavated, callous. 



Dimensions. — Length 13 mm. ; breadth 21 mm. 



Form, and Loc. — Pliocene : Wanganui, Ifew Zealand. 



G. 9604. A large series illustrating stages of growth. 



Sir James Sector Coll. 



1 Tryon's Manual of Conchology, vol. xi. 1889, pp. 15, 457. 



