142 SYSTEMATIC ARRANGEMENT 



a. Turbina. Body cylindrical. Aperture of shell and operculum 

 subcircular. Shell top-shaped ; front of whorls convex. 



* Operculum without spiral ridges. 



1. Sarmatictjs. 



Operculum externally covered with numerous separate, flat-topped 

 tubercles. Shell top-shaped, thick, imperforate ; outer lip with a 

 submarginal black line of animal matter. 



1. S. Classicarius. Turbo Sarmaticus, Linn. Operculum thin ; tu- 



bercles separate. 



2. S. natalensis. Turbo n., Krauss. Operculum thick ; tubercles 



crowded. 



2. Turbo. 



Operculum externally convex and granular (fig. 77). Shell top- 

 shaped, imperforated or perforated, covered with a periostraca ; spire 

 conical ; aperture circular ; outer lip simple, rather produced in front. 



1. T. araucanus, t. 108. f. 3. Fig. 77. — Inside of operculum 



2. T. radiatus, t. 107 a. f. 2. of Turbo - 



3. T. chrysostoma, t. 41. f. 6. 



4. T. marmoratus, t. 37. f. 1. 



5. T. tuberculosus, t. 38. f. 5. 



6. T. smaragdus, t. 38. f. 1. 



Tongue of Turbo elongate, linear, pale brown. Teeth 00 - 5 - r5"00, 

 in doubly arched series, the inner ones in a concave line, the outer 



Fig. 78.— Teeth of Turio ? (Antarctic Expedition). 



in a convex cross line ; central tooth linear, dark red, rather dilated 

 and truncated at the tip ; inner lateral teeth elongate, ending in an 

 elongated compressed hook ; outer lateral teeth elongate, ending in 

 an elongated hook, the inner one large, and gradually diminishing in 

 size to the outer edge (fig. 78). 



