Diario de tasty_y

Splitting clausilia dubia and c. pumila is notoriously hard, and there aren't many good photos on the internets anywhere, especially not of pumila. I'll try to put some helpful info here for my own use and convenience as much as for anybody else reading it.

My own comparison photos:

Photos by Aleksandr Anichtchenko, size not to scale:

Photos from a book by Digna Pilāte, no unambiguous attribution:

My own doodle with a summary, exaggerated:

This looks to be the case where the overall shape matters as well as the opening grooves - pumila seems noticeably longer and club-shaped, this is true.

Here are all the good links for identifying molluscs that I know (besides the obvious). I'll collect them here mostly for my own convenience, but also for whoever may need them. Sadly, not all the materials are in English. Feel free to post your favorite links in the comments.

• Swedish website: very slick, a list of Swedish species and distribution maps. Nice pictures, some species have multiple pictures of different morphs, which is especially nice. Somewhat lacking when it comes to bivalves. In Swedish.
• German website: a similarly slick database, everything in 𝔊𝔢𝔯𝔪𝔞𝔫. Species, distribution maps (well hidden) and even identification keys. Especially noteworthy: 𝔇𝔢𝔯 𝔖𝔠𝔥𝔩𝔦𝔢ß𝔪𝔲𝔫𝔡𝔰𝔠𝔥𝔫𝔢𝔠𝔨𝔢𝔟𝔢𝔰𝔱𝔦𝔪𝔪𝔲𝔫𝔤𝔰𝔰𝔠𝔥𝔩ü𝔰𝔰𝔢𝔩 (whatever that is), the Pea Clam section (with pretty pictures!) and the accompanying 𝔈𝔯𝔟𝔰𝔢𝔫𝔪𝔲𝔰𝔠𝔥𝔢𝔩𝔟𝔢𝔰𝔱𝔦𝔪𝔪𝔲𝔫𝔤𝔰𝔰𝔠𝔥𝔩ü𝔰𝔰𝔢𝔩 @amr_mn, may be relevant to your interests.
• Carnegie Museum is the only resource on American snails that I know. Snails of Virginia section is especially good, also has a snails of Pennsylvania section, less complete.
• Molluscs of Belarus (in Russian). Not so great pictures, but lots of info on various species.
• Swiss Database (thankfully in English) - mostly distribution maps. Also pretty slick.
• Ukrainian Gastropods: Gural-Sverlova may have contributed a lot to it? Lots of valuable info, though scattered all over the maze-like web-page.
• British distribution maps.
• French Clausiliids - not a website, but a paper with a key. Includes sub-species, very detailed.
• Nature of Latvia - Latvian species lists and distribution maps. Sad, pitiful.
• Another American page