INTRODUCTION 



Ixxiii 



A still nearer approach to the higher avicularium occurs 

 in the remarkable form described by Smitt under the name 



Fig. xxXT. 



Fig. xxxvi. 



Memhranifora princeps. 



Diachoris Magellanica. 



oi Membranipora minax (Woodcut, fig. xxxv.)"^. Here 

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



Fig. XXXV ii. 



Fig. xxxviii. 



Avicularium of Notamia. 



to. Tactile organ. a. Aperture. 



c. Chamber, s. Stem. 



Cell of 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 M. minax, Busk ; and I should propose 

 for it the name of M. princeps. Compare the fixed avicularium of this 

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

 fig. xxxyi.). 



