Hurrox.—ÓOn some Branchiate Gastropoda. —— 119 
smallest; the anterior surface straight, and the sides truncated. Operculuin 
ovate, with the nucleus subapieal; horny, transparent round the margin, 
the middle portion chestnut red, deeply trilobed on the inner edge. 
The specimens figured were collected at Lyttelton. 
TnaorHow pusius, Hutton. Pl. XIII., fig. E. 
Animal of a bright salmon-red colour. Dentition.—Odontoglossate, the 
lateral teeth not being versatile. Central tooth small, rectangular, longer 
than broad, with three small acute rather distant cusps; lateral teeth 
broad, curved, with seven cusps; the inner small, the next five subequal 
and close together, the outer small and distant from the others. Operculum 
ovate, subconcentric. 
The specimens figured were collected in Auckland. The dentition shows 
that this species belongs to the Fuside, while its smooth columella and 
fusiform shell put it into the Fusing: the operculum, however, is quite 
different from any other species of the family, and it must therefore be 
placed in a new genus, which I propose to call Taron. 
NEPTUNÆA DILATATA, Quoy and Gaimard. Pl. XIII., fig. F. 
Dentition.—Central tooth arched with four rather long cusps with 
rounded points of which the two inner are slightly the larger ; posterior 
margin deeply concave. Lateral teeth with three curved cusps, the outer 
longer and distant from the other two. Operculum oblong, rather unguicu- 
late, nucleus apical. 
I am indebted to Mr. T. F. Cheeseman for specimens in spirit from 
Auckland. 
- Professor Troschel has given a figure of the dentition of this species 
(Das Gebiss der Schnecken, ii. taf. vi., fig. 17) which differs very much 
from mine, and I cannot account for the difference. 
Neprun#a noposa, Martyn. Pl. XIIL, fig. c. 
Dentition.—Central tooth quadrate, the breadth three times the length, 
with four subequal triangular eusps placed close together. Lateral teeth 
as in the last species, but the cusps more curved. Operculum like that of 
the last species. 
The specimen figured was sent me from Auckland by Mr. T. F. Cheese- 
man. 
EvrHRIA LINEATA, Chemnitz. Pl. XIII., fig. m. 
Dentition.—Central tooth deeply curved, and the ends bent backward; 
a single tricuspidate cutting-point in the centre: laterals with three sub- 
equal and equidistant cusps. Operculum oval, the nucleus apical. 
The specimen figured was collected at Lyttelton. The dentition of this 
species is quite different from that of its supposed variety C, figured in the 
Trans. N.Z. Inst., xiv., pl. vi, fig. p. This latter must therefore be 
