Another risk in dealing with radulae is the possibility of ontogenetic change.  Feeding habits may change as a mollusk grows up; corresponsingly, the radula may change.  Strict reliance on any one character is likely to get you into trouble in classification, as shown by most of the higher-level classifications of the bivales, for example.  Radula characters aren't helpful for them, either (nor in any of the snails that have lost the radula).

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL  35487-0345 USA
    [log in to unmask]

That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa

----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------