210 



In tho following descriptions the shells are considered sinistral. 



Planouijih lentub. — Dene. Shell dull brownish or yellowish 

 brown, sub-carinatc above, particularly in the young shell; whirls 

 nearly five, striate across with five, raised, subcfjuidistant lines, 

 forming grooves between them j spire concave; aperture large, em- 

 bracing a large portion of the penultimate volution ; labrum more 

 acutely, but not very prominently arquated above, its basal portion 

 horizontally Huhrectilincar in the adult and not extending below 

 the level of the base. 



Obs. I obtained this species in the canal at New Orleans and I 

 indebted to Mr. Maclure and also to Mr. IJarabino for many fine 

 specimens collected in tlie vicinity of that city. 1 also found the 

 same speci(;H at Ojo de Agua, Mexico, when travelling in that 

 country willi Mr. Maclure. It differs from the following species 

 in having the labrum less prominent above, and the basal portion 

 of this part being in the adult horizontally subrectilinear so as not 

 to touch a plane on which the base of the shell may rest; the 

 aperture also is more tranHverse. PI. 54, fig. 1. 



Planokijih TRivoJiViK. — 1*. trivolvu, S., Amcr. Ed. aj 

 Nlr.k(»UorC n Eacijc, ArlvMi Conckotofji/ , pi. 2, f. 2. 



(JochlfAij Irmm orhium, JAatar., (Jonch. jjI. 140, /. 40. 



Petiver, Gaz<yphyl. pi. lOG, /. 17. 



Ohn. This is an inhabitant of the Middle and Northern States 

 and is very common in many districts. I have found it in Penn- 

 sylvania, New Jersey, Delaware, Maryland, Falls of Niagara. 

 Upper (JaMada,and in the vicinity of (council IJluff on the Missouri. 

 Dr. Eights sent me specimens from Albany, New York, and 

 Mr. Jossup gave several from Cayuga lake. Lister gives two 

 pretty good figures of this shell and quotes Virginia as the native 

 locality. Muller, (imelin and Dillwyn, incorrectly referred to 

 Jiister's figures as IliUx (dhcMd, but the latter author in his edition 

 of Lister iigrees with us in considering them as representations (^f 

 the present species. 1*1. 54, tig. 2. 



I'lanoimitk IMCAHINATUK, S. Amcv. Ed. of NichohorCs Enci/i 

 Ai'lkle Conckolofj;//, pi. l,fif/. 4. 



Helix anf/ulaluH, Racket. lAun. Trans, vol. 13, p. 42, p/. 5, 



P. bicurvnafMH, Sow<rhi/» (Jciiera. 



Ohs. It is an inhabitant of tho same extensive region as the 



