Figure lih. — Magellania Wyvillii Davidson. 



FiGURK IW. — I\lageUania flavescens Lamavok. 



Figure He. — Magellania kerguelenensls Davidson. 



Figures EJ, Fi, Gb, He. — Ontogeny of Magellania (^Neoihyris) len- 

 iicularis Deshayes, from the magadiform to the magellaniform stages. 



Figures Ec, Fc, Gc. — The magadiform, magaselliform, and terebratelli- 

 form stages of Terehratella cruenta Dillwyn. 



Figures Ed, Fd, Gd. — The same stages in Terehratella ruhicunda 

 G. B. Sowerby. 



Figure E. — Magas pumilus Sowerby; the Cretaceous prototype of 

 this structure. 



Figures E/, Fe. — The magadiform and magaselliform stages of Mag- 

 asella Cumingi Davidson. 



Figure \)h. — Megerlina Lamarchiana Davidson; adult form of 

 brachial supports. 



Figure Cb. — Kraussina rubra Pallas ; adult ; showing septum and 

 two branches. 



Figure Cc. — Kraussina pisum Valenciennes apud Lamarck. 



Figure Cd. — Bouchardia rosea Mawe ; adult ; showing thickened 

 cardinal process, hinge-plate, and ring on the septum as in Ca. 



