xxiv. CONCHYLIA— D/rHFEJ. 



** Cochlearibus horizontali-protensis. 



Vfiih the teeth projecting horizontally. 



4. declivis, latere antico truncato. 



the anterior end truncate. 



5. praetenuis, latere antico rotundato. 



the anterior end rounded. 



7. arctica, latere postico truncato. 



the hinder end truncate. 



6. distorta, margine sinuato. 



the margin indented. 



J 5. LiSTEEA. 



1. compressa, Listera. 



16. Amphidesma. 



1. prismaticum, valvd altera denticulo simplici et lateralibus. 



in one valve a simple denticle and lateral teeth. 



2. tenue, valvd altera denticulo Jisso et lateralibus. 



in one valve a cloven denticle and lateral teeth. 



3. Boysii, valvd altera denticulis duobus et lateralibus. 



in one valve two denticles and lateral teeth. 



17. Agina. 

 I. purpurea, Agina. 



18. Ervilia, 

 1. uitensj Ervilia. 



