EXPLANATION OF PLATE IX. 



Fig. 1. Niso, sp. Vertical section of a species from the Tertiary beds of 

 Muddy Creek, Victoria — x 3. 



„ 2. Niso (Vetotuba) brazieri, Eth. fil. Portion of a specimen, partly 

 in relief and partly in broken section, showing the umbilical 

 tube. 



3. The same. Specimen with ten whorls. 



4. Cyclonema australis, Eth. fil. Portion of an individual showing 

 the general features of the species. 



5. The same. Portion of the surface ornament — x 0. 



G. Oriostoma, northi, Eth. fil. Upper view of a nearly complete 

 specimen. 



7. The same. View of the back. 



