8 TROCHUS. 



Section INFUNDIBULOPS Pilsbry. 



Similar to Infundibulum, but the columella thin straight and 

 simple from its insertion in the center of the false -umbilicus to its 

 union with the basal lip. Type, T. erythneus Brocc. 



Indian 0. 



Differs from Infundibulum in lacking the strong fold of the 

 columella. 



Section CCELOTROCHUS Fischer. 



Similar to Infundibulops, but with the false-umbilicus very deep 

 and narrow, penetrating deeper than the columella which is inserted 

 upon its edge, not in the center of the axis. Type, T. tiaratus Q. 

 et G. New Zealand. 



Section ANTHORA Gray. 



Shell elevated, conical, granulose above, lirate below; base plano- 

 concave, false-umbilicus shallow, bicostate, outer and basal lips 

 smooth within, columella oblique, with a small fold above, its edge 

 simple. Type, T. viridis Gmel. New Zealand. 



Section PR/ECIA Gray. 



Columella twisted, simple; false-umbilicus deep, narrow, with a 

 distinct narrow central spiral rib ; throat striated. Type, T. ele- 

 gantulus Wood. 



Section BELANGERIA Fischer. 



Shell conical, solid ; outer lip of aperture lirate within ; columella 

 with a small fold above, its base curving and denticulate where it 

 unites with the denticulate basal margin ; false umbilicus narrow, 

 Type, T. scabrosus Phil. 



Subgenus CLANCULUS Montfort, 1810. 



Shell conical, conoidal or turbiuate ; generally granose-lirate all 

 over ; periphery rounded or angular, base flat or convex, false- 

 umbilicate ; aperture oblique, usually obstructed by teeth, the outer 

 lip usually lirate or dentate within, columella with a tooth-like fold 

 above, terminating in a tooth at the base ; false umbilicus with a 

 crenated border. Type, T. pharaonius Linn. 



Mediterranean, Indian 0., and Pacific. 



Genus MONODONTA Lamarck, 1799. 



Shell imperforate, turbinate, ovate or globose-depressed, the 

 periphery rounded ; surface smooth or spirally ridged ; columella. 



