Haldeman, S.S. 1841. Descriptions of four species of Cyclas, three of which belong to the subgenus Pisidium: and two species of Cypris. Proceedings of the Academy of Natural Sciences of Philadelphia 1: 53. Available electronically.
Haldeman, 1841. Proc. Acad. Nat. Sci. 1: 53.
Haldeman, 1841. Proc. Acad. Nat. Sci. 1: 53.
Haldeman, 1841. Proc. Acad. Nat. Sci. 1: 53.
Haldeman, 1841. Proc. Acad. Nat. Sci. 1: 53.