H. Shaler Williams, ?On the revision of the mollusk genus Pterinea, Goldfuss?, Proceedings of the United States National Museum, vol. 34, pp. 83-90, 1908.

H. Shaler Williams, ?Some new Mollusca from the Silurian formations of Washington county, Maine?, Proceedings of the United States National Museum, vol. 42, pp. 381-398, pls. 49, 50, 1912.

H. Shaler Williams, ?On the revision of the mollusk genus Pterinea, Goldfuss?, Proceedings of the United States National Museum, vol. 34, pp. 83-90, 1908.