EXPLANATION OF PLATE 20. 

 (See page 8.) 



Fijr. Name of Species. Where Described. 



1. Cytherea mortoni Con Jr. Phila. Ac. Nat. 8c., Ut er., vol. 7, 



1H5M, p, 150, 



3. Cytheroa dUooidalU (!on ... Few. Hli. Tor. Form., 1H88, p. 87, p. [50] 



3. Gratcluptu hydana Con " " " p, 8, p. [58] 



(Describod as a Cythcn-ii) 



4. Cytlicrca perovatu Con ... Fos. Sh. Tor. Fiwm., 1HSJ8, p. 87, p, [59] 



5. Cytherea al-quorca Con ,. M I P- t 58 ! 



6. Cytherea subcimsa Lea. ..._ Cont. to Geol., 1838, p. 67, pi. 2, flg. 43. 



7. Cytherea poulsoni Con....... FOSB. Sh. Ter. Form., 1H33, p. 36, p. [58] 



[110] 



