734 The Smithsonian Institution 



II," including fresh-water and marine Pulmonata, or "Pul- 

 monata Limnophila and Thalassophila," as well as "Part 

 III," embracing the Pectinibranchiate and Rhipidoglossate 

 gastropods (" Ampullariidae, Valvatidse, Viviparidae, fresh- 

 water Rissoidae, Cyclophoridae, Truncatellidee, fresh-water 

 Neritidae, Helicinidae "), appeared as early as 1865 ; and both 

 were prepared by William Binney alone. It may be added 

 that proof-sheets of both those parts were quite widely sent 

 out in book form to specialists ; and the investigations and 

 criticisms to which they were subjected entailed works differ- 

 ing very widely in their final form from the proof examples 

 circulated, and thus rendered evident the wisdom of the 

 course of seeking further information before final publication. 

 "Part IV" was devoted to the " Strepomatidae (American 

 Melanians)," and was not published till 1875. Its author was 

 George W. Tryon. 



In the four parts of the " Land and Fresh-water Shells of 

 North America " thus published, all the species found in the 

 United States and the Dominion of Canada were described 

 and illustrated. The Gastropoda were the only forms in- 

 cluded, and these were for the first time embraced in a con- 

 tinuous series. 



The species of the class known at the time of publication of 

 the several volumes were apportioned to various groups. Part 

 I included the pulmonate land shells; part II the pulmonate 

 aquatic shells; and parts III and IV the gilled aquatic and land 

 shells. 



Part I. Pulmonata Geophila .... 286 



" I Limnophila ... 127 



Part II. " < Thalassophila . . 4 



" ( (Siphonariidae) . . 131 



( Pectinibranchiata 57 



Part III. *..-. 



( Rhipidoglossata 1 1 



68 

 Part IV. Pleuroceridae 444 



