40 THE NAUTILUS. 



S. coosaensis Walker. Quite different from any other species. 

 Apex not prominent nor much elevated. Apical whorl flatly 

 rounded, very rapidly enlarging, scarcely everted, not constricted 

 by the suture, which is deep, but vertical. Apical tip not 

 turned down, but up. Sculpture, wrinkled and punctate above, 

 lirate below. 



S. crassilabris Walker. Apex subelevated. Apical whorl 

 rounded, constricted by a rather deep suture, everted and ob- 

 liquely flattened above. Sculpture, strongly and regularly 

 spirally punctate above from the tip, lirate below. 



S. currierianits Lea. Apex rather prominent. Apical whorl 

 rather low, nearly flat above, convexly rounded, but not con- 

 stricted by the suture and not everted. Sculpture, spirally 

 punctate-lirate above, lirate below. 



S. decipiens Walker. Apical whorl very slightly everted, 

 obliquely flattened above, low, not constricted by the suture. 

 Sculpture, wrinkled at first, then spirally punctate above, lirate 

 below. 



S. depressus Tryon. Apex rather blunt, but higher and more 

 rounded than in integer. Apical whorl slightly everted, obliquely 

 flattened above, but not constricted by the suture. Sculpture, 

 punctate or malleated, more decidedly than in integer ; no trace of 

 lira?. 



S. excavatus Walker. Only a single specimen sufficiently 

 perfect to show any trace of the sculpture. In this, the erosion 

 is not sufficient to destroy the shape of the apical whorl, but 

 the sculpture is very indistinct. Apparently, it is irregularly, 

 transversely wrinkled, but no distinct punctations are visible. 

 The apical whorl is flatly rounded above, but not constricted 

 by the suture. The apical tip is not immersed, but projects 

 above the surrounding whorl. 



S. georgianus Walker. Apical whorl prominent, elevated, not 

 much constricted by the suture, much everted and obliquely 

 flattened above. The second whorl is shouldered. Sculpture 

 spirally punctate. 



S. hendersoni Walker. No specimens with perfect apices. 

 Apical whorl much elevated, though variable in this particular, 

 more or less everted, usually much so, and constricted by the 



