170 "A STROPODA . [Aspidobranchia. 



Genus 1. ETHALIA, A. Adams, 1855. 



Ethalia, A. Ad., P.Z.fS., 1853 (1855), 189. Type: E. guamense, Q. & G. 

 Liotrochus, P. Fischer, J. de Conch., 1878, 207. 



Shell orbicular, turbinately depressed ; whorls convex, smooth or 

 transversely striated, the last rounded at the periphery ; umbilicus 

 partly closed by a callus deposit ; columellar lip ending anteriorly in 

 an obtuse dilated callus. 



The species are moderate-sized shells, depressed, the whorls con- 

 vex, with a mottled or streaked colour-pattern. The callus emitted 

 at the columellar-parietal angle of the aperture is tongue-shaped, 

 closing the umbilicus except a rather narrow chink, or even entirely 

 in some species. 



1. Ethalia zelandica, Hombron and Jacquinot, 1854. Plate 39, 

 figs. 9, 9a. 



Rotdla zelandica, H. & J., Voy. P.S., v. 53, pi. 14, f. 5, 6. Ethalia zelandica, 

 H. & J., Man. Conch. (1), xi, 459, pi. 58, f. 9, 32, 33; pi. 59, f. 66 : Suter, 

 P. Mai. S., ii, 283. Rotella lineolnta (Lam. ?), Gray, in Dieff. N.Z., 238. 

 Globulus anguliferus, Philippi, Conch. Cab. (1853 ?), 51, pi. 8, f. 3. Um- 

 bonium chalconotum, A. Adams, P.Z.S.. 1S53 (1855), 188. V. zelandicum, 

 A. Adams, i.e., 189. 



Shell depressed, imperforate, yellowish or pinkish. Sculpture : Sur- 

 face smooth, base showing under a lens very fine, close, regular spiral 

 striae. Colour yellowish or pinkish, radiately streaked with chestnut- 

 brown or red above, base with a reddish or purple zone around the 

 central callus, the outer part white, more or less striped radiately. 

 Epidermis thin, shining, red and green reflections from the nacre are 

 visible through it. Spire low, conoidal. Protoconch small, convexly 

 depressed, brown, smooth, of 2 whorls. Whorls 6 to 7, first slowly, 

 then more rapidly increasing, the last 2 whorls concave above, the 

 compressed periphery of the last whorl encircled by 2 rather obscure 

 carina? ; base slightly convex, with a narrow spiral groove bounding 

 a central area, which is covered by a thin, radiately rugose, purple- 

 and-white callus. Suture linear, not impressed. Aperture rounded 

 quadrate, nacreous and iridescent within. Outn- ;md basal Up sharp. 

 Columelln short, concave, thick, and heavy, its edge pearly. Inner Up- 

 forming a pad of white callus over the body and the axis. 



Diameter, 19 mm. ; height, 11 mm. 



Dentition unknown. 



Type in the Mus. Hist. Nat., Paris. 



II no. Throughout New Zealand, in the laminarian zone ; Kawhia 

 (Dr. Dieii'enbach) ; Spirit Bay, in 6 fathoms (C;i plain Bollons) ; Ker- 

 madec Islands. 



Fossil in the Miocene and Pliocene. 



Fam. NERITID^S, Lamarck. 



Animal with a short broad muzzle and long slender tentacles, 

 with the eyes on prominent peduncles at their outer bases ; foot 



