1. Extracts from the Proceedings of the Academy of Natural Sciences of Philadelphia, of papers Author(s): Lea, Isaac, 1792-1886 Publication: [Philadelphia? : s.n., 1856?] Subject(s): Alismatales -- classificationFossilsGeologic SedimentsMollusca -- classification
2. Extracts from the Proceedings of the Academy of Natural Sciences of Philadelphia, of papers Author(s): Lea, Isaac, 1792-1886 Publication: [Philadelphia : Merrihew & Thompson, 1857] Subject(s): Alismatales -- classificationFossilsUnio -- classification
