874 Transactions of the Society. 



hyaline lunate or concavo-convex area close to and on central side of 

 each process, and close to each of these a narrower and longer straight 

 transverse hyaline band. Colour pale grey. Central space round, 

 inconspicuous, 005 to O'0O75 mm. broad. IMarkings delicate, 

 granular strine radiating from the central space, between the hyaline 

 areas curved and converging towards tlio processes, on the outer 

 portion still more delicate and slightly convex towards the processes ; 

 apiculi small, numerous, chiefly between the outer ends of the straight 

 hyaline bands, elsewhere sparsely and irregularly placed. Processes 2, 

 circular, about • 01 mm. broad, with border striated. 



An oblique view of one of Grove's specimens indicates the presence 

 of delicate striae on the girdle at right angles to its margin. 



Habitat : Oamaru deposit (Grove & Sturt ! liae ! Hardman ! 

 Kitton !). 



§ 6. CONVOLUTI. 



Transverse median areas sharply defined, those between the cen- 

 tral space and processes undifferentiated. Markings large areolate, 

 unequal, somewhat pearly. 



A. convohdus sp. n. 



Elliptical, major axis O'Ol mm., about If times minor. Surface 

 rising but slightly at the processes ; the transverse median areas 

 somewhat oblique, their outer ends rounded, reaching close to the 

 border. Central space sub-diamond-shaped, sometimes minute. Mark- 

 ings separated by narrow clear lines, those on the transverse areas sub- 

 regular, with the clear intervening lines straight or curved, and but 

 slightly oblique to the long axes of the area ; a distinct band surround- 

 ing the base of each process. Processes 2, elliptical, 0"0175 mm. 

 broad, inserted close to the border. — PI. XV. fig. 2. 



Habitat : Oamaru deposit (Grove !). 



§ 7. Ornati. 



Transverse median areas and the areas between central space and 

 processes evident, widest towards their peripheral ends. Markings 

 forming punctate, closely arranged strisc. Processes large, simply 

 rounded, or sides concave, but towards their base and free ends 

 convex. 



A. lunatus Grove & Sturt in litt. 



Elliptical, major axis 0"08, about 1\ times minor. Surface with 

 the transverse median areas large, the edges diverging outwards, the 

 outer angles rounded, the extremities reaching the border. ^Vt their 

 centre a short transverse elliptical area with outer ends indistinct, 

 an indistinct lunate band close to inner edge of processes. Colour 

 pale smoky grey. Central space round, indistinct, • 0U5 mm. broad, 

 lyiarkings minute punctate, striae converging to processes and 

 diverging from central space indistinct. Apiculi numerous, minute. 



