155 



of the apical wliorls is almost flat-sided, the posterior one is- 

 globose, with the tip laterally immersed. Whorls bluutly 

 angled and tuberculate behind the anterior suture, the posterior- 

 slope is very wide and slightly convex ; the tubercles are 

 rounded, widely separated, eight to a whorl, vanishing half-way 

 across the posterior slope, but reaching the anterior suture ;, 

 spirally lirate, lirae acute, about 20 on the penultimate whorl, 

 alternately large and small on the anterior half, closely striated 

 transversely. 



Last whorl medially angulated and tuberculated, gradually 

 attenuated into a broad, open, much curved shortish beak. 

 Aperture oval ; outer lip thin, faintly lirate within ; columella 

 with a strong plait at the front decurrent on the canal, behind 

 which is a second, and though moderately strong, is hardly 

 visible from without. 



Length, 42'5 ; breadth, 20"5 ; aperture, length 16, width 9 ; 

 length of canal, 11. 



Locality. — Grastropod-bed of the Eiver Murray Cliffs, near 

 Morgan. 



4. Peristernia Murrayana, sine. nov. 



Shell ovately fusiform, whorls six and a half, of rapid in-- 

 crease ; spire short conic, ending in a moderately large obtuse 

 apex of two whorls, 1'5 mill, in diameter ; for about a third of 

 a whorl from the margin of the pullus the surface is slenderly 

 costated, the posterior whorl is globose, with the tip central 

 and partially immersed. 



Whorls bluntly angulated and tuberculated at the anterior 

 suture, the posterior slope very wide and slightly concave; 

 tubercles small, eight to a whorl, trisected by three strong 

 lirse ; ornamented on the anterior half of "the whorl with three 

 or four strong spiral threads, with threadlets in the furrows,, 

 the posterior slope with fine spiral and transverse striae hardly 

 or not at all visible to the unaided eye. 



Last whorl subangulated and tuberculated at the periphery, 

 at the base suddenly contracted into a narrow, nearly closed, 

 sinistrally bent canal. Aperture oval ; outer lip thin, slightly 

 effuse at the front, faintly lirate within ; columella with an 

 oblique conspicuous plait arising from the pillar, and with two 

 to four small linear ridges behind. 



Length, 25'5 ; breadth, 12'25 ; aperture, length 9, width 6 ;. 

 length of canal 6. 



Locality. — One of the commonest fossils in the E-iver Murray 

 Cliffs near Morgan. 



This species is much like P. Morundiana, but is'only about half 

 the size, and differs by its more rapidly increasing whorls,, 

 smaller and trisect tubercles, almost smooth on the posterior 



