TURBO. 191 



Geuus Turbo Liun., 1758. 



Shell turbinate or de^jressed, imperforate or umbilicate; young 

 not carinated nor spinose; base convex; operculum- flat or concave 

 inside, with three or four whorls and subcentral (multispiral) 

 nucleus; outside convex, smooth, tuberculate, or with concentric 

 ribs. 



The diversity of forms of both shell and operculum in this genus 

 is very great, and has caused the formation of numerous subgenera. 

 The affinities of the minor groups I have attempted to express in 

 the following table : 



Central teeth without cusps. 



Turbo, 



Callopoma, 



Ninella, 



Modelia, 



Occma. 



Central teeth with cusps, operculum f ,r i. 



convex, granular, ( 



Central teeth with cusps, oi)erculum ( o i- 



^ ^ \ barniaticus. 



tuberculose,. ( 



Central teeth with cusps, oiierculum f d • j. 



. , , \ Jrrisogaster. 



with submarguuil nucleus, ( 



Subgenus Turbo s. str. 



Shell large or moderate in size, turbinate; whorls rounded, smootli' 

 or ribbed, spinose or carinated, umbilicate or imperforate; aperture 

 subcircular, more or less produced at base. Operculum circular, 

 with subcentral nucleus; outside convex, granulate or smooth, not 

 spiral nor ribbed. 



Indo-Pacific Provivce. 



Synonyms: Olearia Klein, Senectus Swainson. 



Three subdivisions may be distinguished, diflferiug in unimportant 

 characters: Turbo, (restricted), shell large, dilated at base, imperfor- 

 ate; whorls smooth or nodulous. Senectus (Humph.) Swainson, 

 shell generally perforate; whorls spirally lirate. Batillus ^cXwvoa., 

 shell inflated, imperforate ; whorls spinose ; operculum with a convex 

 spiral rib outside. The dentition is essentially the same in all. 



T. MARMORATus Linn., 1758. PL 41, flg. 23. 



Shell large, imperforate, solid, ventricose, as broad as long, green, 

 marbled with white and rich brown; whorls 6-7 flattened or con- 

 cave above, rounded and bearing two nodose keels below, and a 



