38 HELIX-AMPELITA. 



expanded, basal narrowly reflexed ; terminations of peristome con- 

 verging, the ends joined by a very thin, translucent parietal callus. 



H. LANX Femssac. PI. 8, figs. 7, 8, 9. 



Shell depressed, with a very broad umbilicus, chestnut-brown, 

 darker below, often lighter around the umbilicus ; last whorl deflexed 

 below the peripheral carina at aperture ; basal lip straightened or a 

 little projecting in the middle. 



The form is nearly discoidal, spire low, convex, periphery 

 carinated, the carina becoming more obtuse on the latter part of the 

 whorl. It is rather thin ; brown and somewhat shining above, 

 polished and of a rich chestnut color below the periphery, somewhat 

 lighter around the umbilicus. The surface has obliquely-radiating 

 low waves on the upper whorls, scarcely apparent in the typical form ; 

 it is lightly obliquely striate ; within the umbilicus the surface is cut 

 into a fine decussated pattern by incremental striae and close, fine 

 spiral incised lines: Whorls 4i, almost flat, separated by slightly 

 impressed sutures, the last whorl large, carinated, somewhat mallea- 

 ted or rugose near the aperture, descending below the periphery of 

 the preceding whorl, and deeply constricted behind the basal lip. 

 Aperture very oblique, purplish or bluish-white inside, the superior 

 lip very slightly, narrowly expanded, outer lip expanded, basal lip 

 straightened in the middle, columella expanded ; parietal wall with 

 a mere wash of transparent callus. Umbilicus very broad, funnel- 

 shaped, showing all the volutions. 



Alt. 27, greater diam. 60, lesser 50 mill. 



Alt. 22, greater diam. 55, lesser 46 mill: 



Madagascar. 



H. lanx FEE. Histoire, t. 65, f. 7. PFEIFFER, Symbolse i, p. 41 ; 

 Monographia i, p. 392 ; Conchylien Cabinet, p. 209, t. 106, f. 1-3. 

 KEEVE, Conch. Icon., f. 171. H. radama LESSON, Voy. de la 

 Coquille, p. 384, t. 7, f. 1, 1826 ; Cent. Zocl., t. 9. 



This is a rather thin, large species, more or less corrugated on the 

 spire, finely decussated inside the broad umbilicus. 



Var. RADAMA Lesson. PI. 8, figs. 10, 11. 



More transversely inflated or oblong in contour, very distinctly 

 corrugated above. Alt. 25, greater diam. 57, lesser 42 mill. The 

 specimen figured by Lesson measures 90 mill, in diameter. 



