146 Trans. Acad. Sci. of St. Louis. 



EXPLANATION OF ILLUSTRATIONS. 



Plate XL 



1, LampsiUs alata Say; la, right valve of same, showing fold. — 2, Unto 

 gibbosus Barnes. — 3, LampsiUs ligamentina Lamarck. — 4, Unio gibbosus 

 Barnes. — 5, LampsiUs UgamenUna Lamarck. 



Issued November 26. 1901. 



