142 



Transactions of the Society. 



are bean-shaped, and devoid of a swimming-ring ; these, therefore, 

 do not float, but fall to the bottom of the pond or lake. 



Paludicella is a gymnoliemate Polyzoon, and has therefore no 

 statoblasts. It produces, however, small winter buds, or " hiber- 

 nacula," which serve the same purpose. The hibernacula are soft 

 when first formed, and adhere to submerged stones, or rootlets of 

 trees and reeds, when tlie zooecium dies down, to start life again in 

 the spring by budding. Examples of these are also shown. 



Some Polyzoa, besides statoblasts, produce also from fertilized 

 ova ciliated and free-swimming larviB. Some of these, derived 

 from PlumatcUa fHiigosa,\vd\e-heen beautifully mounted by Mr. 

 Hurrell, of Great Yarmouth, and show the double embryo growing 

 within the larval form before it becomes fixed. I have also here 

 a slide of young Pluniaiella fungosa emerging from the statoblasts, 

 and these are always single polypides. 



I have here brought together the statoblasts of all the species 

 I liave in course of time come across. Of these there are eight 

 British species, one comes from Cape Colony, one from Ehodesia, 

 one each from America and Germany, two from India, and three 

 from Japan. 



List of Statoblasts of Fresh-water Polyzoa. 



1. Lophopus crystallinus 



2. L. capensis 



?i. L. carter i 



4. LophopodeUa lliomasi 



5. Cristatella mucedo . 



6. Pectinatella mcKjnifica 



7. P. burnanica 



8. P. Davenporti 



9. P. gelatinosa . 



10. StepJianella hina (Oka) 



11. PlumateUa repens 



12. P.fructicosa . 



13. P. punctata 

 11. PlumateUa sp. (?) 



15. Ditto 



16. P. tanganyilcae 



17. P. fungosa 



18. Ditto 



19. Ditto 



20. Fredericella sultana . 



21. Paludicella articulata 



22. PlumateUa or AlcioneUa 



23. PaludiceUa articulata 



From Kiiglaiid. 



„ Cape Colony (Yalkenburg 

 Vlei). 



„ India (Bombay Presidency). 



„ Tihodesia. 



„ England. 



„ Hamburg. 



,, India (Igatpuri Lake). 



„ Japan. 



„ Japan. 



„ Japan. 



,, England. 



„ England. 



„ Dundee. 



„ South AustraUa. 



,, Surrey Commercial Docks. 



„ Lake Tanganyika. 



,, Hadley Wood. 



„ Surrey Canal. Young emerg- 

 ing. 



„ H. E. Hurrell. Free-swim- 

 ming ciliated larvffi. 



„ Great Yarmouth. 

 Winter buds, or " hibernacula." 

 Sessile statoblasts. 

 " Hibernacula " bursting open. 



