PLATE IV. 



Sabinotrochus flatiliseptis. X 2. 



Sabinotrochus bipatella. X 3. 



Discotrochus dentatus. x 270- 



Desmophyllum alabastrum. - 2. 



Desmophyllum alabastrum. > 4. 

 Fig. 28, 281^, 28<5. Flabellum lamellulosum : natural size. 

 Fig. 29, 2 9rt, 2 9<5. Flabellum suluense. x 1V3- 



Flabellum dens, x 2^/3. 



Placotrochides dentiformis. x 4. 



Placotrochides scaphula. x 5. 



