243 



Fig. 3b. „ pelagicus, Torr. Type. From South Australia. 



4- „ niger, Torr. Type. From Western Australia. 



5- „ manheivsianus, Bednall. From South Australia. 

 5a. „ - matthewsiamis. Median valve, edge on. 

 6. Ischnochiton (Haploplax) misimaensis, Ashby. Type. From Papua. 

 6a. „ „ misimaensis. Type. Anterior valve. 

 6b. „ „ misiviaensis . Type. Median valve. 

 6c. „ „ misimaensis. Type. Posterior valve. 

 7 a, b, c. Lophochiton johnstoni, Ashby. Type. From Western Australia. Anterior, 



median, and posterior valves. 

 „ 8. Cryptoplax michaehcni, Thiele. Type. From Western Australia. 



Plate XVII. 

 Fig. 1. Lophochiton johnstoni, Ashby. Type. From Western Australia. 

 „ 1 a, b, c. Lophochiton johnstoni. Type. Anterior, median, and posterior valves. 

 „ Id. Lophochiton johnstoni.. Type. Median valve, edge on, showing divergence and slight 



curvature. 

 „ 2a. Ischnoradsia papuaensis, Ashby. Type. From Papua. Anterior valve. 

 " 2b. „ papiiaensis. Type. Inside of median valve showing 2 slits. 



>. 2c. „ papuaensis. Type. Posterior valve. 



„ 3. Sclcrochiton curtisiamis, Smith. From Townsville, for comparison with fig. of S. 



miles, showing different character of girdle scales, etc. 



Plate XVIII. 

 Fig. 1. Onithochiton scholvieni, Thiele. From Carnarvon, Western Australia. 

 „ 2. Tonicia (Lucilina) delecta, Thiele. From Carnarvon, Western Australia. 

 „ 3. Sclcrochiton miles, (Cpr.) Pilsbry. From Carnarvon, Western Australia. Showing 



sculpture and peculiar girdle scales. 

 „ 3 a, b, c. Sclcrochiton miles. Same specimen. Anterior, median, and posterior valves. 



Plate XIX. 



„ 1. Cryptoplax hartmeyeri, Thiele. From Yallingup, Western Australia. 



„ 2. „ rostratus, Reeve. From Sydney, New South Wales. 



„ 2 a, b, c.^ Cryptoplax rostratus. Juvenile. Anterior, median, and posterior valves show- 

 ing shape. 



„ 3. Cryptoplax michaelseni, Thiele. From Carnarvon, Western Australia. 



„ 3 a, b, c. Cryptoplax michaelseni. Same specimen. Anterior, median, and posterior 

 valves showing shape. 



„ 4. Cryptoplax iredalei, Ashby. Type. From South Australia. Minute girdle spicules. 



„ 5. „ striatus, Lamarck. From type locality, South Australia. Coarse girdle 



spicules. 



