KA.sn;i>H)i>.A. 637 



1. Allodiscus Adriana, Button, 1883. Plate 25, figs. 10, 10a. \0h. 



Frttticicola Adriana, Hutt., N.Z.J.S., i, 1883, 470; T.N.Z.I., xvi, 175. 

 Psyra Adriana, Hutt., t.c., 201. Gerontia (Allodiscus) Adriana, Hutt. : 

 Pilsbry, Man. Conch. (2), viii, 07. Allodiscus Adriana, Hutt. : Hedley 

 and Suter, P.L.S. N.S.W. (2), vii, 039. Flammulina (Allodiscus) Adriana, 

 Hutt. : Suter, .1. de Conch., xli, 252 ; Man. Conch. (2), ix, 15. 



Shell small, discoidal, perforated, finely ribbed, thin, not shining. 

 Sculpture consisting of delicate fine flexuous radial riblets, 20 to 2~> 

 per millimetre, absent on the embryonic whorls, but extending on the 

 base to the perforation ; interstices with fine growth-lines, reticulated 

 by microscopic spiral lines, which are also visible on the protoconch. 

 Colour pale corneous with spots and angular streaks of chestnut, absent 

 upon the base. Epidermis thin, membranous, not shining. Spin 

 flatly convex, about two-thirds the height of the aperture. Proto- 

 conch of H to If whorls, the nucleus slightly raised. Whorls 44-, 

 slowly increasing, convex, periphery regularly rounded ; base convex, 

 with a central depression. Suture impressed. Aperture slightly ob- 

 lique, rotundly lunar. Peristoma thin, regularly arched. Columella 

 very short and oblique. Inner !//> slightly reflected. Perforation. 

 narrow and open, somewhat hidden by the reflection of the peristome. 



Diameter Maj.. 4mm. ; min.. 3-5 mm. : height. 1-75 mm. (type). 



Animal unknown. 



Type in the Canterbury Museum. Cluistchurch. 



Hob. North Island : Cape Maria van Diemen (McGahey) ; Mount 

 Pirongia (T. Urquhart) ; Mount Egmont, 3,000ft. to 4,500ft,, and 

 Toko, near Stratford (R. Murdoch) ; Otaki Gorge (H. B. Preston) ; 

 Napier ; Forty-mile Bush (H. S.) ; Shannon, Manawatu (R. Murdoch) ; 

 Ormondville (Chad wick). South Island : Banks Peninsula, type (R. 

 Brown) ; Springburn (Professor Dendy) : Governor's Bay (H. S.). 



The species is nowhere common. 



2. Allodiscus Cassandra, Button, 1883. Plate 9, figs. 2. 'In. 2/>. 



Champa (?) Cassandra, Hutt., N.Z.J.S., i, 1883, 470; T.N.Z.I., xvi, 181. 

 Psyra Cassandra, Hutt., t.c., 201. Gerontia (Allodiscus) Cassandra, 

 Hutt. : Pilsbry, Man. Conch. (2), viii, 06, pi. 22, f. 37-39. Allodiscus 

 Cassandra, Hutt, : Hedley and Suter, P.L.S. N.S.W. (2), vii, 038. Flam- 

 mulina (Allodiscus) Cassandra, Hutt. : Suter, .1. de Conch., xli, 251 ; 

 Pilsbry, Man. Conch. (2), ix, 15. 



Shell rather large, depressed, imperforate, thin and fragile. Sculp- 

 ture of protoconch consisting of microscopic radial and close spiral 

 lines ; the following two or three whorls are radially distinctly ribbed, 

 the ribs first close together but gradually becoming more distant and 

 less prominent until on the last whorl there are only well-marked 

 dose and flexuous growth-lines ; the interstices between the riblets 

 with numerous close and fine growth-striae, crossed by fine and dense 

 microscopic spiral lines. Colour corneous, with radially angulatcd 

 .bunds of chestnut. Epidermis thin, membranous, but faintly shining. 



