BICELLARIELLIDAE 395 



6. Avicularia of typical bird's-head form. Zooecia in three sections Bicellariella 



Avicularia not of bird's-head form (often columnar or trumpet-shaped). Zooecia in two 



sections Cornucopina 



7. Zooecia not forked proximally, connecting-process at bifurcation forming an axillary 



chamber, some at least, of the avicularia 1 with very long stalks Camptoplites 



Zooecia forked proximally, no axillary chambers formed, avicularia not long-stalked 8 



Avicularia 1 of bird's-head form. Operculum without distinct rim Bugula 



Avicularia 1 not of bird's-head form. Operculum with distinct chitinous rim . . . Himantozoum 

 Zoarium uniserial with longitudinal connecting tubes at bifurcation ... Erymophora 



Zoarium laminate and fenestrate, the zooecia connected by four or six radiating tubes; or 



uniserial without longitudinal connecting tubes Beania 



1.1.1.1-1,1 



8 







A.B 



'5mm 



Fig. 27. A. Bicellariella sp. St. WS 776, Patagonian Shelf. Zooecia at bifurcation lettered according to 

 Harmer's scheme. B. Farciminellum antarcticum sp.n. St. WS 42, South Georgia. Ovicell. C. Diagram 

 to illustrate upper and lower head-angles of avicularia. 



av. avicularium. 



1 Avicularia are absent in a few species, e.g. Camptoplites atlanticus, Bugula neritina, Bugula longissima 

 and Himantozoum antarcticum. 



