PLATE XXI. 



no;. 



1. TUBULAHIA LARYNX, p. 118, nat. size. The Author. 



1 a. A polypitej magnified. From a drawing by Mr. 



Alder. 



2. TUBULAKIA CORONATA, p. 119, liat. size. 



2 a. A cluster of gonophores, magnified. The Author. 



2 b. A single gonophore, highly magnified, to show the 



contained embryo. After Van Beneden. 



3. TUBULARIA BKLLIS, p. 122, nat. size. 



3 a. A cluster of gonophores, magnified. The Author. 



4. ECTOPLELRA DuMORTiERii, p. 121, nat. size. The 



Author. 



4 a. The gonozooid, magnified. After Van Beneden. 



