The Shell-Collector's Handbook. 45 
thin, glossy; mouth oval, with a notch at its base ; 
outer lip thin and not reflected ; umbilicus wanting. 
Famity V.—Carychiide. 
Shell spiral, oblong; mouth oval, dentated; um- 
bilicus very minute. Eyes situated at the hinder base 
of the dorsal tentacles ; lower tentacles rudimentary. 
25. Carychiidium, Miill. 
Famity VI.—Cyclostomatide. 
Shell cylindrical or conical, operculated ; mouth 
round or oval; operculum testaceous or horny. 
26. Cyclostoma, Drap.—Shell conical; opercu- 
lum testaceous. 
27. Acme, Hartm.—Shell cylindrical; operculum 
horny. 
