PLATE XII. 



BiMERIA VESTITA, GaRVEIA NUTANS. 



Fio. 



1. Bimeria vestita, magnified. 



2. The same, natural size. 



3. An ultimate ramulus of same, carrying a male sporosac, much enlarged, to show the structure 



of the sporosac with its ramified spadix. 



4. Garveia nutans, magnified. 



5. The same, natural size. 



6. Distal portion of tentacle of same, much magnified. 



7. A female sporosac of same, much magnified : a, ectotheca invested by a delicate chitinous 



pellicle ; b, mesotheca ; c, endotheca ; d, rudimental radiating canals in the proximal 

 portion of the mesotheca. 



8. A male sporosac of same. 



9. Spermatozoa of same. The mode in which the head of the spermatozoon is occasionally 



curved upon itself is here seeu. 



10. Planula of same. 



1 1 . Yoiuig of same, developed from the planula. 



