66 PROF. ALLMAN ON STEPHAXOSCYPHUS AIIRABILIS. 



DESCRIPTION OF PLATE. 

 Plate XIY. 



Pig. 1. Stephanoscyphus mirabilis, with its investing sponge : nat. size. 



2. Perisarcal tubes of the same freed from the sponge : nat. size. 



3. A group of zooids magnified, a, the animal fully exserted and the tentacles extended; b, the 



animal partially retracted ; c, the animal with the tentacles thrown hack over the sides of the 

 tube ; d, the animal completely retracted ; e, an empty perisarcal tube : the internal ehitinous 

 processes are seen through its walls. 



4. Distal portion of a tentacle seen in optical longitudinal section : more highly magnified. 



5. Longitudinal section through a perisarcal tube and the retracted animal, from a specimen preserved 



in spirit : a, a^mternal ehitinous processes. 



6. Transverse section of same through one of the verticils of ehitinous processes. 



7. Thread-cell from bodv. 



