5S4 DISCINIDiE. 



Species of Crania. 



anomala, Mull. ringens, Haningh. 



personata, Lam. rostrata, Hceningh. 



radiosa, Gould. 



Fam. DISCINIDjE. 



Animal with its oral arms fixed to a process of the lower 

 or ventral valve. 



Shell horny, minutely tubular, attached to marine bodies 

 by a short tendinous peduncle which passes through a 

 fissure in the hinder part of the ventral valve ; upper or 

 dorsal valve conical and patelloid. No hinge or apophysary 

 system. 



If the lower valve in these animals corresponds to the 

 perforated valve of the Terehratulida, the oral arms will be 

 fixed to the ventral instead of to the dorsal valve, so that 

 they cannot be said to repose on their backs like most 

 other Brachiopods. 



Genus DISCINA, Lamarck. 



Shell horny, orbicular ; upper valve conical, limpet-like, 

 without any internal processes ; lower or ventral valve per- 

 forated near the hind part for the passage of the peduncle, 

 and furnished internally with a central process for the at- 

 tachment of the ciliated arms. 



Syn. Orbicula, Sow., not Cuv. 



Ex. D. lamellosa, Broderip, pi. 132, fig. 4. Shell, D. 

 lamellosa, fig. 4, a, 4, b. 



The shell in this genus is horny, and when moist and 



