74 Notes on Certain Terrestrial Mollusks. 



Macrocyclis concolor, Fer. 



This species, judging from its great similarity, if not 

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



Shuttleworth (Diag. n. Moll. 1854) mentions, on the 

 authority of Blauner, that 31. 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 (subgenus of Hyalina), which must now, however, 

 be treated as a synonyme of Macrocyclis. 



M. laxata, Fer., is the type 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 ; 31. Vancouverensis, sportella, Voyana and 

 Duranti. In eastern Nortfh America, 31. 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 ; 31. euspira to Venezuela. 



Zonites Lansingi, nov. sp. 



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

 basi substriatula ; sutura hnpressa; anfr. 5£ convexiusculi, ultiraus non 

 descendens, ad peripheriam obsolete angulatus, subtus convexior, circa 

 regionera umbilicarem excavatus ; apertura anguste lunaris ; peristo- 

 mate acuto, margine 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 ; whorls 6& 

 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. 1 J mill. 



