Hovrros.—0On new Tertiary Shells. 821 
Locality, Wanganui and Petane. 
Rissoa semisulcata, 
Shell minute, pupiform, thick. Whorls 5, flattened ; the first three or 
four smooth ; the last, or the two last, smooth anteriorly, but with four 
shallow but well marked spiral grooves on the posterior half. Suture 
distinct. Aperture roundly ovate, not notched anteriorly ; peristome con- 
tinuous. 
Length, ‘1 inch. 
Locality. Wanganui. 
Rissoa rugosa. 
Shell robust, pupiform, roughish. Whorls 6 or 7 ; the first 14 polished, 
the others of the spire longitudinally plicated with one spiral rib and a 
sulcus behind and two in front of the plications; plications more or less 
nodulose. Body whorl sometimes not longitudinally plicated, the posterior 
half with about 8 spiral ribs, the anterior half smooth. Aperture broadly 
ovate, the peritreme continuous and rather patulous. 
Length, :17 inch. 
Locality. Petane. 
Rissoa impressa. 
Shell small, pupiform. Whorls 5, the two first smooth; the others 
longitudinally plicated; base of the body whorl smooth; a single spiral 
groove just below the suture, which is margined. Aperture broadly ovate ; 
peritreme continuous and rather patulous. 
Length, *08 inch. 
Locality. Petane. 
Rissoa gradata. Pl. xviii., fig. 21. 
Shell small, ovate, cancellated. ^ Whorls 5, gradated ; the two first 
smooth and polished; the others longitudinally and spirally ribbed. 
Longitudinal ribs about 15 in a whorl. Spirals—a posterior one near the 
angle, and two anterior ones with a smooth band between. On the body 
whorl there are about 7 spirals in front of the smooth band and the longitu- 
dinals become obsolete. Suture impressed. Aperture roundly ovate, not 
notched in front; peritreme continuous. 
Length, :1 inch. 
Locality. Wanganui and Petane. 
Scalaria nympha. 
Shell small, turreted. Whorls slightly rounded, very finely spirally 
striated and longitudinally ribbed. About 18 or 20 ribs and one or two 
varices in each whorl. Suture impressed. Body whorl keeled anteriorly, all 
the longitudinal ribs ending abruptly at the keel ; the base slightly concave 
and smooth below the keel. Aperture sub-rotund. 
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