IN PRODUCTION. 



Ixxiii 



A still nearer approach to the higher avicularium occurs 

 in the remarkable form described by Smitt under the name 



Fig. XXXY. 



Fig. xxxvi. 



Membranipora princeps. 



Diachoris Magcllanica. 



of Membranipora minax (Woodcut, fig. xxxv.)*. Here 

 we have the perfect form of the " bird's head " (a curious 



Fig. xxxviii. 



Avicularium o/Notamia. 



to. Tactile organ. a. Aperture. 



c. Chamber. . Stem. 



Cell o/Notamia, with 

 avicularium. 



anticipation of the organ as it exists in Bugula Murray- 

 ana] : but there is no basal joint, and the whole structure 

 is calcareous. A connexion is very clearly established 



* This is certainly distinct from Af. minax, Busk ; and I should propose 

 for it the name of Af. princept. Compare the flied aricularium of this 

 species with the movable bird's head of Diachorit Magellanica (Woodcut, 

 fig. xxx vi.). 



