Remark: introduction signed May 1853; mentioned in Proceedings of the Academy of Natural Sciences of Philadelphia ( 6: lxxvi) in combination with the date 1 November 1853. For the wrapper see Figure 3. [Also known under the title Monographia Heliceorum viventium. Supplementum. Sistens enumerationem auctam omnium huius familiae generum et specierum hodie cognitarum, accedentibus descriptionibus novarum specierum et enumeratione fossilium].