TURRtTELLA. 207 



Section ZARIA, Gray, 1847. 

 T. DUPLTCATA, Linn. PL 65, figs. 20-22. 



Whorls about 16, stout, ponderous, the first few with several 

 subequal keels, afterwards first one keel and then a pair of them 

 are developed more strongly, whilst the others become faint or 

 obsolete, everywhere closely spiral^ striate ; fulvous cream color, 

 becoming light chestnut towards the apex. Length, 5-6 inches. 



Indian Ocean. 



T. replicata and T. acutangula, Linn. (fig. 21), are synonyms. 

 In the latter the second prominent keel is not developed. 



Var. ATTENUATA, Reeve. Fig 22. 



Reeve attempts to distinguish this from T. acutangula by the 

 want of the single prominent keel, but the variations between 

 these forms are infinite, so that attenuata can barely stand as a 

 variety. T. acutangula, Desh., not Linn., is a variety. 



T. FERRUGINEA, Reeve. PI. 64, fig. 11. 



Whorls 16, convex, finely spirally ridged, first whorls two- 

 keeled, keels gradually fading, the lower whorls becoming 

 obtusely subangulated below the middle; whitish, longitudinally 

 undulately strigate with chestnut. Length, 3'75 inches. 



Hab. unknown. 

 T. AUSTRALIS, Lam. PL 65, fig. 23. 



Whorls about 12, with deep suture, encircled by a prominent 



central nodulous carina, and a less prominent subnodulous on*e 



below the suture, spirally striate ; yellowish brown, brown banded 



on the base. Length, 1 inch. Australia, Tasmania. 



T. granulifera, Woods, is a synom-m. 



Section TURRITELLOPSIS, Sars, 1878. 



T. ACICULA, Stimpson. PL 64, fig. 12. 



Small, turreted, subulate, thin, white; whorls 10, very convex, 

 longitudinally striate and spirally ribbed; aperture rounded, 

 effuse anteriorly, peristome acute. Length, 5 mill. 



Cape Cod, northwards ; Norway to Sitka. 



Distinguished from the young of T. erosa by its much more 

 convex whorls and prominent ribs. T. tenuisculpta, Carp., is a 

 synonym. 



