What are the main features of smithii. Shell pattern and body colour are pretty useless for IDing species. What colour is the columella, parietal wall, inside of shell lip? How twisted is the columella? What size is the aperture in relation to the shell? What shape is the aperture. How many whorls, is the lip strengthened of calloused? What is the sculpture on the whorls, particularly the early whorls, and specifically the nepionic whorl (the one's they hatch with)?
I think I will write a guide to what we need to ID a snail. Most times, people post a picture of the snail that although may look like a good representation of the snail, doesn't focus on the bits that matter. The shell obviously helps with a quick ID sometimes, it's easy to spot fulica usually or reticulata etc. But as soon as it is hard to decide they are of no use whatsoever.
Bequaert mentions smithii in reference only. So it's up to you smithii owners to find all of this info out. If you can tell me what the answers are we can create a species template so-to-speak.
For instance, according to Bequaert there hasn't ever been a fulica with a red columella (although he admits it is possible). So that should be ID point number one for fulica. If it looks like a fulica and has a white or blueish-white columella, it probably is.
well the body looks like fulica. but the shell is just a bit more slender, with yellow stripes.
Again, how slender the shell is, is of no importance in a lot of cases, just look at fulica. You get thin ones, coned ones, ventricose ones, non-venticose ones; a huge variety of shapes and profiles. So I don't think it is of any use unless as a contributing but secondary factor to help decide. Measure the whorls, the proportion between them (particularly the body whorl) matters and the aperture size and the shell sculpture.
In some species where shell profile matters - usually where the spire part is radically different than the body whorl or in cases where the shape is extreme - we need to see pictures from directly above and below, to help decide. Pictures taken at an angle don't show very much, mainly because there is perspective and can't be measured.
If you take a picture from overhead and below then the pixels can be counted for measurement purposes, probably easier and more accurate than trying with a ruler in most cases.