36G THE PROCEEDINGS OP THE LINNEAN SOCIETY 



20. — RlSSOINA. SP. 1 



Hab. Katow, New Guinea, 8 fathoms, mud bottom. Cape 

 York, Mud Bay, North Australia, 4 fathoms, mud bottom. Off 

 York Island, Torres Straits, 13 fathoms, hard yellow mud bottom. 

 Specimens all dead and sea worn. 



21. — RlSSOINA. SP. % 



Hab. Darnley Island, Torres Straits, 25 fathoms, sandy 

 mud. One specimen found dead and sea worn. 



22. — Rissoina. sp. 1 



Hab. Warrior Island, Torres Straits. Two specimens found in 

 shell sand, dead and worn. 



23. — Rissoina. sp. 1 



Hab. Darnley Island, Torres Straits, 25 fathoms, sandy mud. 

 Specimens dead and sea worn. 



24. — Rissoina. sp. 1 



Hab. Darnley Island, Torres Straits, 25 fathoms, sandy mud 

 bottom. One specimen found dead and sea worn. 



25. — Rissoina. sp. ] 



Hab. Darnley Island, Torres Straits, 25 fathoms, sandy mud 

 bottom. One specimen found dead and sea worn. 



26. — Rissoina efficata. n. sp. 



Shell elongate, solid, white, smooth ; whorls 7, flattened, the 

 three upper having two spiral granulated ridges on the centre of 

 the whorls ; suture deep, aperture semiovate ; inner lip moderately 

 callous, outer lip very much thickened, white, slightly sinuated 

 anteriorly. 



