HELIX-EUHADRA. 121 



oblique, irregularly ovate, lunate ; peristome thickened, white, a 

 little reflexed ; margins distant, the columellar margin oblique, 

 dilated into a rather thick callus which almost entirely covers the 

 umbilicus, joining the basal margin in a tuberculiform prominence; 

 the basal margin nearly straight, the outer arcuate and excavated. 

 (Mabille.} Alt. 21, greater diam. 31, lesser 26 mill. 



Tonquin. 



H.jaculata J. MAB., Moll. Tonk. Diagn., p. 5, May, 1887 ; Bull. 

 Soc. Mai. Fr. 1887, p. 86, t. 1, f. 8, 9. 



This species belongs to the same group as H. bathymophora, but 

 differs from that form in its more globose outline, more elevated but 

 more obtuse spire, etc. 



H. MERCATORINA Mabille. PI. 15, figs. 67, 68. 



Shell umbilicated, globose-subdepressed, solid, shining, buff, 

 radiately ribbed-striate, and a little crispate ; spire strong, convex- 

 mamillated,apex, obtuse, shining, ruddy ; whorls 6, convex, rapidly 

 and regularly increasing, separated by a distinct linear suture ; the 

 last whorl large, convex-rounded, a little dilated and descending in 

 front, a little convex beneath ; aperture oblique, lunate, oblong- 

 rounded ; peristome expanded, a little thickened, white, reflexed, the 

 margins distant, outer ( margin excavated and incurved, columellar 

 margin nearly straight, dilated in a pretty thick callus which is not 

 appressed but projects a little over the umbilicus ; columella thick, 

 oblique, with a strong tubercle at its base. (Mabille.} 



Alt. 17, greater diam. 31, lesser 25 mill. 



Tonquin. 



H. mercatorina MAB. Bull. Soc. Mai. Fr. 1887, p. 88, t. 2, f. 10, 

 11. 



H. MERCATORIA Gray. PL 31, figs. 26, 27. 



Shell with a narrow, deep umbilicus, of a depressed form, convex 

 below, conoid-convex above the obsoletely subangular periphery ; 

 thin but moderately strong, chestnut-brown, encircled at the periph- 

 ery by a narrow darker girdle, which is bordered above and below 

 by light yellowish bands ; the dark girdle is visible at the suture of 

 penultimate whorl ; the inside of the umbilicus is perceptibly darker 

 than the color of the base. The surface is nearly lusterless, with 

 strong curved stride, more prominent above. Spire low-conoidal, 

 apex obtuse ; suture evenly impressed ; whorls 6, slightly convex, 

 slowly widening, the last obsoletely angular at the periphery, de- 



