222 A MANUAL OF AMERICAN LAND SHELLS. 



Jaw as usual in the geuus. 



Liugual membrane (Terr. Moll., V, Plate III, Fig. I) witli 2o-l-L*5 

 teeth ; 3 laterals and 1 transition tooth on each side. 



Zoiiites placeiitula, Siiuttlewouth. 

 Shell widely umbilicated, very much, depressed, arctispiral, very 

 shining, marked by irregular, distant, impressed striie, horn- 

 color, diaphanous, below of uniform color; whorls 7, most 

 gradually increasing, scarcely convex, the last convex below, 

 subexcavated around the umbilicus; aperture oblique, lu- 

 nate; peristome simple, acute. Greater diameter 7i, lesser 

 (Jimm. height, 3'"™. 

 Near Z. demissus, but most readily distinguished by its 

 z.piacentuia. j^^^.^ depressed shell, its wider umbilicus, and especially bj^ 

 the absence of the heavy, opaque, white callus in the aperture on the 

 base of the last whorl. (Shuttl.) 



Zonites placeniula, Siiuttleworth, Bern. Mit., 1852, 194.— Gould, in Terr. Moll., iii, 

 19.— Pfeiffer, Mon., iii, 631.— W. G. Binney, Ann. N. Y. Ac. Sc, i, pi. xiv, 

 fig. A. 



A species of the Cumberland Subregion, having been received from 

 the mountainous region of Tennessee (Jalapa, «&c.); from Whitley 

 County, Kentucky ; from Lexington, Ya. I have also received it from 

 the Hot Springs of Arkansas, proving that it has the southwestern 

 range beyond this subregion noticed in many of its species. It is also 

 quoted, but incorrectly, from Colorado by Ingersoll. 



Animal with distinct locomotive disk, longitudinal furrows, and cau-' 

 dal mucus pore. 



This species has been confounded with Z. capsella, but differs greatly 

 in many particulars, especially in its general outline, number of whorls, 

 width of umbilicus. There are sometimes 8 full whorls. 



The jaw and lingual membrane described as those of this species in 

 Terr. Moll., V, are no doubt those of Z. LawL 



Zonites Wlieatleyi, Bland. 



Shell umbilicated, depressed, thin, shining, pellucid, brownish liorn- 



FiG 237 colored, finely striated ; spire subplanulate ; suture slightly 



impressed ; whorls little convex, the last more convex at the 



base, rapidly increasing, at the aperture scarcely descending; 



umbilicus jjervious; aperture depressed, obliquely lunate; 



peristome simple, acute, the margins approximating, joined 



by a thin callus. Greater diameter 5, lesser 3i'"'" ; height, 2"^™. 



Z. WheaUeyi. Zonites Wheatleiji, Bland, Ann. N. Y. Ac. N. Sc, ii, 368, fig. 1 (1883). 



