180 Transactions. — Zoology. 



Distinguished by its keeled whorls. 



Animal unable to withdraw completely into its shell ; the mantle rather 

 broadly reflected over the margin ; eye-peduncles short and stout, separated 

 at their bases ; orange-yellow, the upper sides thickly marbled with black ; 

 head between the peduncles bright orange ; the peduncles and tentacles 

 black. 



Jaw nearly straight, thin, striated in the centre, and slightly folded 

 towards the ends. 



Dentition, 28-1-28. Laterals about 9. 



Central tooth rectangular, rather longer than broad ; the reflexed por- 

 tion tricuspid, the .lateral cusps hollowed on the outer side, median cusp 

 clavate, reaching nearly or quite to the posterior margin of the base. The 

 laterals are like the central tooth, but the cutting point on the median cusp 

 gets larger as they recede from the centre ; the outer laterals have a small 

 point on the inner cusp, and the outer cusp vanishes. Inner marginals 

 bicuspid, each with a cutting point, the inner of which is the smaller ; the 

 middle marginals have about 5 points, of which the two inner are much 

 larger ; in the outer marginals these two larger points diminish, and at last 

 all disappear. 



Hah. Greymouth (E. Helms). 



Amphidoxa lavinia, n. s. 



Shell sub-discoidal, umbilicated, ribbed ; colour yellow horny, mottled 

 with rufous on the upper side. Spire flat ; periphery rounded ; suture 

 scarcely impressed ; whorls 3-|, rapidly increasing, rather flattened above, 

 rounded below ; upper surface not shining, evenly and closely ribbed ; ribs 

 about 18 in the tenth of an inch ; lower surface smooth, shining, longi- 

 tudinally striated, and irregularly spirally striatulated ; umbilicus mode- 

 rate, showing all the whorls ; aperture oblique, rotundly lunar ; peristome 

 thin, the margins approaching ; columellar margin not reflected. Greatest 

 diameter -5, least -4 ; height '25 inch. 



Hah. Palmerston, Wellington (T. W. Kirk). 



Chakopa miranda, n. s. PI. ix., fig. w, and pi. xi., fig. s. 



Shell minute, depressed, imperforate, finely ribbed ; colour pale horny 

 tessellated with rufous. Spire flatly conoidal, obtuse; whorls 5-6, rounded, 

 very slowly increasing ; the first smooth, the second and third with rather 

 distant, delicate ribs, which get closer and after the third whorl are very 

 close and fine, about 50 in the tenth of an inch ; umbilicus very narrow, 

 covered ; suture impressed ; aperture subvertical, lunate ; peristome simple, 

 about three-fourths of a circle, the columellar margin slightly callous and 

 reflected. Greatest diameter -15, least *14 ; height -11 inch. 



