188 ZONITES. 



Var. VENUSTA, Strebel. PI. 5C>, fig*. 71, 72. 



Commonly with a broad sutural band and another on the base, 

 with a narrower band above the periphery; sometimes the two 

 upper bands unite into one, when the color may be stated better 

 as chestnut, with a peripheral light band, and the middle of the 

 base light. 



Var. PALLIDA, Tryon. Fig. 72. 

 Shell uniformly olivaceous-yellow, no banding. 



H. TUXTLENSIS, Crosse and Fischer. PI. 56, figs. 73, 74. 



Umbilicated, thin, slightly shining, subpellucid, with very 

 thin, suboblique hair-like striae, chestnut-color, with light fulvous 

 corneous sutural line, a band of same color above the periphery, 

 and the centre of the base; whorls 5, slightly convex, regularly 

 increasing; aperture livid white, showing the supraperipheral 



zone. Diam. 22*5 mill. 



Tnxtla, Vera Cruz, Mexico. 



Like var. venuxta of H. bilineata, but larger, more globose, less 

 depressed, scarcely shining, distinctly striate, wider umbilicus, etc. 



Section PATULOPSIS, Strebel, 18SO. 



II. CARINATA, Strebel. PL 56, figs. 75-77. 



Rather widely umbilicated, thin, translucent, finely costulate- 

 striate above, smoother and shining below, light or dark brownish 

 horn-color; whorls 4^-5, moderately increasing, somewhat slop- 

 in gly flattened above, periphery angulated, base convex. 



Diam. 9 mill. 



Jalapa, Mexico. 

 Section ^EGOPINA, Kobelt, 1879. 



II. ZONITOM^EA, Letourneux. PL 56, figs. 78-80. 



Narrowty, profoundly umbilicated, fragile, pellucid, obliquely 

 striulate, corneous white, becoming corneous olivaceous towards 



O 



the aperture and yellowish towards the apex; whorls 6j, regu- 

 larly, slowly increasing, a little angulate on the periphery, 



rounded below, suture impressed. Diam. 22 mill. 



Algiers. 

 H. OLIVETORUM, Herm. PL 56, figs. 81-85 ; PL 57, 88-94. ' 



Widely, perspectively umbilicated, thinly striulate, shining, 

 suture impressed ; whorls 5^, moderately increasing, somewhat 



