N'otes on Certain Terrestrial MoUusks, 74 



Macrocyclis concolor, Fer. 



This species, judging from its great similarity, if not 

 identity, with 31. Baudoni, is doubtless a Macrocyclis, 



Shuttle worth (Diag. n. Moll. 1854) mentions, on the 

 authority of Blauner, that M, concolor is viviparous. In the 

 Swift cabinet a specimen is preserved, which he had alive, 

 and from which he took five embryo shells. What the habit 

 is in that respect of the North American species of Macro- 

 cyclis has not been noticed. 



M. concolor and Baudoni are placed by v. Martens in 

 Morchia [suhgenus of Hyalina) , which must now, however, 

 be treated as a synonyme of Macrocyclis. 



M. laxata, Fer., is the tj^pe of that genus, but its denti- 

 tion is, I believe, unknown. 



The geographical distribution of the species shows that 

 Macrocyclis is essentially an American genus. 



In the Pacific Province of the Northern Continent, four 

 species are found ; M. Vancouverensis, sportella^ Voyana and 

 Duranti. In eastern North America, M. concava, H. pau- 

 cispira, Poey, of Cuba, will, I think, prove to be a Macro- 

 cyclis, M. concolor belongs to Puerto Rico, and Baudoni to 

 Guadaloupe and Dominica; M, euspira to Venezuela. 



Zonites Lansingi, nov. sp. 



T. imperforata, orbiculato-depressa, fusco-cornea, superne laevigata, 

 basi substriatula ; sutura impressa ; anfr. b^ convexiusculi, ultimas non 

 descendens, ad peripheriam obsolete angulatus, subtus convexior, circa 

 regionem umbilicarem excavatus ; apertura anguste lunaris ; peristo- 

 mate acuto, margiue dextro lamella obsolete serrata intus incrassato, colu- 

 mellari vix reflexiusculo. 



Shell imperforate, orbicular-depressed, shining, dark horn- colored, 

 smooth above, at the base substriate; suture impressed; vrhorls 5^ 

 rather convex, the last not descending, obsoletely angular at the periph- 

 ery, more convex at the base, excavated around the umbilical region; 

 aperture narrow, lunate; peristome acute, the right margin thickened 

 within by an obsoletely denticulated lamella, columellar margin scarcely 

 reflected. 



Diam. maj. vix 3, min. 2^ mill., alt. Umill. 



