Philadelphia, PA, J. Dobson, 1838. 8vo (21.1 x 15.6 cm). viii, 80, [vi] pp; 51 plates [numbered 1-32, 34-50, followed by two without number] (Plate 45 pencilled). Later half morocco over marbled boards. Spine with five raised bands, and gilt title. Marbled endpapers.

A rare and notoriously complicated work, published in parts over a very long period. The title is confusingly similar to Conrad's earlier (1832-1835) Fossil shells of the Tertiary formations of North America, illustrated by figures, drawn on stone, from nature, from which it also took a few engravings. The American malacologist and malaco-historian Richard Irwin Johnson (1925-2020) made an unpublished collation of this work of utter rarity, from which it becomes clear that the text of the last-issued Part 4 is lacking, as are pp. ix-xvi of the introduction. This is in fact the rarest part of all. Plates 3, 9, 11, and 19 in first edition. Plate 9 is printed by "T. Sinclairs Lith. Phila.", and numbered XXII. In another copy it is numbered 9 and printed by "Lehman & Duval Philad.a". The present plate might be from the Journal of the Academy of Natural Sciences of Philadelphia, it shows the same specimens, but differs in details. It is preceded by a leaf numbered IX, with a pencilled shell of the related Dione reposta. Plate 45, also of Part 4, is an old, pencilled reproduction, loosely inserted. Bound in is a note in an old hand, stating: "The following descriptions of plates 45, 46, 47, 48, and 49 were copied, including erasures and substitutions, from Mr. Conrad's slip in the copy of the 'Fossils of the Tertiary Formations of the United States', 1838, in the library of the Academy of Natural Sciences of Philadelphia". Plate 33 was never issued. There is no reference in the text to this plate. In the rear are two plates depicting Chamidae, apparently belonging to a different work, viz. S. F. Holmes's Post-Pleiocene fossils from South Carolina (1860). The American malaco-historian Richard I. Johnson noted, in 1979, that "no copy of this work has appeared in catalogues in the past 40 years". Neither was there any in the following 42 years. We found no auction records. Small label of "Joseph McDonough Co. Scarce and Fine books, Albany, N.Y.", and of the palaeontologist Jeffrey D. Stilwell on front pastedown. Plates with species names added in light pencil. Inner joint reinforced with cloth strip; title toned; introductory pages [iii]-viii foxed and toned, as are pp. 25-32, from the same quire; plates with some, mostly mild toning or spotting, all other pages (i.e., the vast majority) on different paper and near clean. Caprotti II, pp. 17-18 [181-182]; Sabin, 15902. Not in Nissen.