136 Transactions. — Zoology. 



margin shortly ascending, rather straight, and slightly reflected over the 

 umbilicus : interior of the aperture strengthened with seven spiral plaits on 

 the body-whorl, and another, rather distant, on the columella ; parietal wall 

 with ten spiral plaits. Greatest diameter 0-08, least 0*07 ; height 0-05. 



Animal. — Body elongated, narrow ; eye-peduncles long and thick, ten- 

 tacles moderate : mantle subcentral, rather anterior, enclosed : foot very 

 long and narrow, with neither locomotive disc nor caudal gland. Colour 

 pale grey, eye-peduncles and a stripe on each side of the head purplish ; 

 foot pale brown. Dentition, 12-1-12. 



Hab. Greyniouth (Mr. E. Helms). 



Amphtdoxa coknea, sp. nov. 



Shell thin, depressed, imperforate, striated, translucent ; colour pale 

 horny. Spire slightly convex ; whorls 2£, rapidly increasing, rounded, 

 smooth, polished, finely striated with growth-lines ; suture impressed : 

 aperture very oblique, transversely oval; peristome thin, regularly arched, 

 columellar lip slightly reflected. Greatest diameter 025, least 02. Denti- 

 tion, 17-1-17. 



Bab. Auckland (Mr. T. F. Cheeseman). 



From A. compressivoluta this shell may be distinguished by the whorls 

 being convex instead of flattened ; from the other New Zealand species of 

 Amphidoxa by being imperforate, and of a pale horny colour without mark- 

 ings and without ribs. The mantle of the animal is marbled with black, 

 which shows through the shell. 



Amphidoxa costulata, sp. nov. 



Shell small, subdiscoidal, umbilicated, shining but not polished, ribbed ; 

 colour pale horny, longitudinally banded with reddish, the bands absent 

 on the last half of the last whorl. Spire almost flat ; whorls 8^, rapidly 

 increasing, rounded, ornamented with fine spiral striatulations and close 

 ribs, about 40 to 45 in the tenth of an inch, the interstices very finely 

 reticulated ; suture impressed ; umbilicus a narrow perforation at the 

 bottom of a broad funnel-shaped depression, which is ribbed like the rest of 

 the whorls ; aperture oblique, transversely ovate ; peristome thin, regularly 

 arched. Greatest diameter 014, least Ol . Dentition, 14-1-14. 



Hab. Auckland (Mr. T. F. Cheeseman). 



This species is easily distinguished by the ribbing and spiral striatulations. 

 Phrixgnathus, gen. nov. 



Animal heliciform. Mantle subcentral, protected by an external shell, 

 over which it is reflected anteriorly. No locomotive disc to the foot. Foot 

 rounded posteriorly and without caudal gland. Jaw papillate, imbricately 

 folded. Teeth quadrate, the laterals bicuspid. Shell conical or turbinated, 

 of five or six gradually increasing whorls ; peristome thin, straight. 



