HELIX. 119 



destitute of an umbilical opening, -ffhich in that species is 

 large. The singular indentations of the surface resem- 

 ble the indentations of the hammer on the interior of 

 silver vessels, and hence the specific name. In this 

 respect it resembles H. totvnsendiana, Lea, from the 

 same region, which howeveiJ* has a large umbilicus, a 

 widely reflected lip, and a more robust form, like H. 

 exoleta. 



11. HELIX NICKLINIANA, Lea. 

 Plate VI. Figure 1. Plate VI. a. 



H. testa conico-globosa,vix perforata, tenui,leviter striata, 

 concinne indentata et granulata, dilute cornea, rufo-zonata ; 

 spira elevata, anfractibus sex convexis, ultimo ventricoso ; 

 apertura rotundata, labro reflexo, albo. 



SYNONYMS AND EEFEBENCZS. 



Helix Nickliniana, Lea, Trans. Amer. Pliilos. Soc. VI. 100., pi. 23. f. S4. 

 DESCRIPTION. 



Animal. Not observed. 



Shell conic-globose, rather thin, the surface lightly 

 marked by the lines of growth, faintly indented and 

 delicately shagreened with fine microscopic granules 

 arranged in quincunx. It is pale horn-color or some- 

 times cinereous, girdled with a single narrow chestnut 

 brown zone, paler at its edges ; the whole covered with a 

 thin, yellowish-brown epidermis. Spire elevated, whorls 

 six, moderately convex, the outer one ventricose, with 

 some approach to an angular periphery. Base tumid. 



