In a new journal that appears on-line since last year, Folia conchyliologica, I found a paper by C. Audibert on a trip to Mexico, Yucat??n where he highlighted one species: Chaonopoma (Choanopomops) largillierti (Pfeiffer, 1846).
I reproduce here part of Audibert’s figures. His full article may be found in Folio Conchyliogica 5: 4-6. The journal, focussing mainly on European snails, is available on this website: http://cernuelle.com/download.php?lng=fr.