21 



decipher from the clayey pages of this old lake of the 

 Derwent. There are, however, myriads of leaves still uncut, 

 unread, and I trust the members of this Society will assist in 

 the future in adding to our knowledge regarding them. 



DESCRIPTION OF TWO NEW MARINE SHELLS 

 DREDGED OFF THREE HUT POINT, D'ENTRE- 

 CASTEAUX CHANNEL, TASMANIA. 



By C. E. Beddome. 

 [Bead 10th May, 1881.] 



DeLPHINULA JoHNSTONI, U.S. 



Shell minute, obliquely turbinate, nucleus smooth, 

 whorls 3| to 4, convex, latticed by spiral and diagon- 

 ally transverse lirse ; spiral lirae alternately fine and 

 coarse, increasing in number towards aperture ; base 

 convex, the surface of which is also finely latticed ; there is a 

 well-defined, relatively broad, and somewhat concave band, 

 transversely lirate, between last spiral lirae and the tortuous 

 marginal rib of umbilicus, which latter joins and forms a 

 partly closed channel at anterior angle of aperture. Aper- 

 ture round, outer lip simple, obsoletely channelled at anterior 

 and posterior angles. Inner lip reflexed and nearly conceal- 

 ing umbilicus and marginal rib. — Long. 2 mil. Lat. 2 mil. 



This shell is closely allied to J), tetragono stoma, Tenison- 

 Woods (fossil sp.), and forms an interesting link with the 

 marine life of the tertiary period. 



Hab., off Three Hut Point, D'Entrecasteaux channel, about 

 17 fathoms. 



I have great pleasure in dedicating this species to my 

 friend R, M. Johnston, Esq., who has interested himself so 

 much in the i:)resent and past fauna of the country. 

 Leda Lefroyi, n.s. 



Shell minute, thin, translucent, much compressed, narrowly 

 elongate. Under the lens the exterior surface appears 

 finely striated, radiately and concentrically, and is 

 covered with a very delicate olive epidermis. Anterior 

 side short, arched ; posterior side with a gently curved 

 depression, and produced into a long, narrow, tapering 

 rostrum, which, upon the inside, is divided into two well- 

 defined channels by a raised longitudinal callosity in both 

 valves. Rostral area scarcely truncated at the tip. Umboes 

 slightly elevated. Ventral margin slightly convex. Long. 

 9| mil. (a line passing vertically through umboes would 



