Hutton. — On some Branchiate Gastropoda. 119 



smallest ; the anterior surface straight, and the sides truncated. Operculum 

 ovate, with the nucleus subapical ; horny, transparent round the margin, 

 the middle portion chestnut red, deeply trilobed on the inner edge. 



The specimens figured were collected at Lyttelton. 



Trophon dubius, Hutton. PI. XIII., fig. e. 



Animal of a bright salmon-red -colour. Dentition. — Oclontoglossate, 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 subequai 

 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 Fusidce, while its smooth columella and 

 fusiform shell put it into the Fusince, : 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. 



Neptunjea dilatata, Quoy and Graimard. 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 G-ebiss der Schnecken, ii. taf. vi., fig. 17) which differs very much 

 from mine, and I cannot account for the difference. 



Neptun^ia nodosa, Martyn. PL XIII. , fig. g. 



Dentition. — Central tooth quadrate, the breadth three times the length, 

 with four subequal triangular cusps 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. 



Euthkia lineata, Chemnitz. PL XIII. , fig. H. 



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., pi. vi., fig. d. This latter must therefore be 



