Nerita quadricolor or else?

[j.de sousa]

<a href="http://www.badongo.com/pic/7621173" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/7621173">http://www.badongo.com/pic/7621173</a><!-- m --></a> these are Nerita quadricolor to compare with the ones that I think they are another species for one the parietal region is smooth and the spiral cords are thinner than in Nerita quadricolor

[dave r]

Quadricolor to me has thin spiral ribs and less colour pattern, like the two shells bottom-middle and the shell bottom right. The others I am not sure of, they look to me like grossa. As I said, a very difficult and confused complex of Nerites, some consider quadricolor as a synonym of undata.
Dave