EXPLANATION OF PLATE XVIII. 



Fig. 1. Spinosella glomerata, sp. nov. Nat. size. 

 2. Ciocalypta incrustans, sp. nov. Nat. size. 

 3. Gellins aculeatus, sp. nov. Nat. size. 

 4. Agelas gracilis, sp. nov., spicule. Greatly enlarged. 

 5. Polymastia dendyi, sp. nov. Nat. size. 



