156 PLECTOPYLIS. 



vex below, somewhat constricted behind the basal and outer lips. 

 Aperture round-lunate, small, very oblique; peristome slightly 

 expanded, heavily thickened within, white or purplish, the ends 

 somewhat approaching. 



Alt. 82, greater diam. 14 mill. 



Kiowa Station, Limestone Gap and near Eufaula, Indian Terri- 

 tory. 



H. kiowaensis SIMP., Proc. U. S. Nat. Mus. 1888, p. 449. Mesodon 

 kiowaensis W. G. B., Third Suppl. T. M. v, p. 199, figs. Var. 

 arkansaensis PILS., The Nautilus iv, p. 131, 1891. 



This very well-defined species may be a toothless Triodopsis, as 

 Binney suggests. It seems to be very distinct from all other species, 

 but certain forms of H. thyroides have a faint resemblance. 



Var. arkansaensis Pilsbry. PL 50, figs. 11, 12. 



Shell more robust, with larger aperture and smaller umbilicus 

 one-fifteenth the diameter of the shell. 



Alt. 9*, diam. 15-15* mill. 



Near Hot Springs, Arkansas (F. A. Sampson.) 



PLECTOPYLIS (Vol. Ill, p. 159.) 



It should be noted that the name Atopa Alb. cannot be used for 

 the Ceylonese group allied to Plectopylis, on account of the previous 

 use of that generic term in Coleoptera. The name GORILLA Ads. 

 must replace it. 



P. JOVIA Mabille. Vol. IX, pi. 20, figs. 1, 2, 3, 4. 



Shell depressed, discoidal, very broadly umbilicated, the umbilicus 

 regular, funnel-shaped, its width contained not quite 2 times in the 

 diameter of the shell ; solid, opaque, obliquely striatulate and decus- 

 sated by subobsolete microscopic spiral lines above ; reddish under 

 a (deciduous?) yellowish-brown cuticle; lusterless. 



Spire slightly convex, composed of 1} very slowly increasing 

 whorls; the last whorl wider, rather strongly deflexed in front, very 

 convex beneath and obtusely subangulated around the umbilicus. 

 Aperture oblique, rotund-truncate, the peristome well curved, 

 strongly reflexed, its face white and thickened, ends joined by an 

 elevated lobe of the parietal callus, from which an entering lamella 

 arises extending a short distance inward. At the last third within 

 the whorl it is obstructed by a broad, curved, transverse, parietal 



