22 



862 a. 



877 



875 



852 



882 



851 



860 a. 



855 



890 

 893 

 906 

 905 

 895 

 891 

 896 

 900 



912 a. 

 914 d. 

 917 

 915 

 915(1. 

 914 

 909 e. 

 912 d. 

 -916 d. 



(Arca) 



NUCULA 



TRIGONIAN A, 



918 Trigonia pectinata, Lam., New Holland. Asiroi. pi. *8, f. i-4. 



N A I A DA, 



919 Unio* 



MARGARITA, 

 acutissimus. Lea, Alabama. 



Trans. Am. P. S. pi. x. f. 18, v. 4. 



* In the arrangement of the Narades I have adopted the classificalion of Isaac Lea, Esq. of Philadelphia. His 

 " Synopsis of the family Naiades of Lamarck," and also descriptions of several new species, illustrated by beauti- 

 fully colored plates, have lately appeared in the Transactions of the American Philosophical Society, Philadelphia, 

 Vol. VI. Part 1. New Series. 1838. 



