Hi, Conch-Lers!
   I am now fairly clear about the distinction between N. nodosus and N. fragosus.   Now, arthriticus is given as the species name for the knobless Lion's Paw.  But a number of things are not clear to me:  (1) must the shell be completely knobless?  (2) what is the range of this spcies; does the range overlap the ranges of nodosus and fragosus; (3) Are there any other distinguishing characteristics, other than the absense of
knobs?

Thanks ahead of time,
Linda