PLATE X. 



Thigonia diversicostata (page 68.) 

 Figure 1 Left valve of an average example. 



Trigonia, Sp. iindt. (page 70.) 



Figure 2. Left valve of an undistorted individual, with a portion of the outer 

 surface of the test preserved. Part of the right valve is also 

 visible. 

 " 2 a. Left valve of a crushed and exfoliated specimen. 



AucELLA MosQUENSis (?) VoH. Bucli. (page 74.) 



Figure 3. Right valve of a distorted example. 



" 3 a. Portion of the anterior margin above, to show the inflection of both 

 valves just below the beaks. 



Meleagrina amygdaloidea (page 78.) 

 Figure 4. Right valve of the type of the species. 



