TUEEITELLA. 241 



in some living and extinct forms of the adult of this variable 

 species is the diminishing importance of the prominent spiral 

 carina and the corresponding roundness of the periphery of the 

 body-whorl, and slight convexity of the usually flat area of the 

 forepart of that whorl. These features may possibly be charac- 

 teristic of the gerontic stage, but the adult specimens at the 

 writer's disposal are not numerous enough to enable him to 

 satisfactorily determine that point. 



Dimensions. — Lenjjth 84 mm. ; breadth 22 mm. 



Form, and Loc. — Miocene (?) and Pliocene : New Zealand. 



G. 9588. Specimens in which the peripheral keel of the body- 

 whorl is veiy acute, and the anterior area flat and even slightly 

 concave ; from Wanganui. Sir James Sector Coll. 



G. 9700, G. 9701. Examples of the neanic and gerontic stages, 

 the periphery of the body-whorl in the last-mentioned being 

 rounded ; from Parimoa. W. B. B. Mantell Coll. 



G. 9723. Two examples of the adult ; from Onekalcara. 



\_Ol(l Collection.'] 



Turritella kanieriensis, nom. mut. 



18o0. Turritella rosea, Mantell, Quart. Journ. Geol. Soc. vol. vi. p. 331, 

 pi. xxviii. fig. 16 (non Quoy and Gaimard, 1834). 



1873. Turritella [Zaria] tricincta, Hutton, Cat. Tert. Moll. N.Z. p. 13 

 (lion Borson et auct.). 



1893. Turritella tricincta, Hutton, Linn. Soc. N.S."W., Macleay Mem. Yol. 

 p. 63, pi. viii. fig. 60. 



Distinguished by three subequal and equidistant strong spiral 

 carinse, the interstices being spirally striated ; the forepart of the 

 body- whorl is flattened, and covered by closely-set spiral striae ; 

 aperture subquadrate. 



It is closely allied to T. trij)licata, Brocchi, of European and 

 North African Miocene and Pliocene, and still living in the 

 Mediterranean and in the Atlantic; but differs in regard to 

 the sinuosity of the lines of growth and in not having the spiral 

 carinae flattened. Further, in the New Zealand species the carinae 

 are fairly equal in size, whilst in T. triplicata the middle one is 

 the largest, the posterior one being smallest, and this latter 

 IS frc([uently duplicate. Hutton's specific name is here altered, 



