Plicaxis mirabilis (Sykes, 1902)
“Warum Sykes die Gattungsbestimmung dieser in der That wunderbaren Schnecke für zweifelhaft hält, ist mir unerfindlich. Die spiral eindringende Leiste auf der Spindel ist ganz analog der Bildung bei Rhodina perakensis Morg., nur viel stärker augeprägt. Dieser Charakter, welcher schwächer ausgebildet bei Prosopeas rhodinaeforme m. von den Philippinen wiederkehrt, dürfte genügen, um Rhodina Morg. mindestens als Subgenus neben Prosopeas anzuerkennen. Der Kiel auf dein letzten Umgang ist als Art-, nicht Gattungscharakter anzusehen.- Eine Aehnlichkeit mit Rhodea ist nicht zu verkennen, was neben dem Vorkommen der Nenia- ähnlichen Garnieria in Hinterindien immerhin bemerkenswerth ist.” (Möllendorff, 1902)
“Recently, I described and figured a shell from Kelantan, under the name Rhodina (?) mirabilis. I felt some doubt as to whether the form really belonged to de Morgan's genus, as the single species he referred to it was, and is, unknown to me. Dr. Moellendorff expressed the view that the form did really belong to de Morgan's genus. Whether this be so or not the name Rhodina cannot be used in Molluscs, having been employed by Guenee in 1854 for an Australian butterfly. Under these circumstances I propose the new genus Plicaxis and take as the type my Rhodina (?) mirabilis. I feel but little doubt that de Morgan's R. perakensis also belongs here. Dr. Moellendorff suggests that the group should be reduced to a subgenus of Prosopeas, but it appears to me to be distinct from the typical Nicobar forms; it may be remarked, with regard to this last name, that Prosopea and Prosopeus had previously been used in Zoology.” (Sykes, 1903)
“This species is the type of the genus Plicaxis, though Mr. Sykes did not actually use the combination Plicaxis mirabilis.” (Pilsbry, 1906)
Sykes (1902) original descriptions on Rhodina (?) mirabilis – “Shell recalling in form Rhodina perakensis, de Morgan, but the earlier whorls increase more rapidly, and the lower half of the shell has a more cylindrical appearance. The columella is twisted, and a revolving keel encircles the base and ascends spirally into the shell, about half way up the columella wall; in addition, another keel is visible from the junction of the suture line and the outer lip until, revolving round the periphery, it fades out where it bisects the outer lip. Whorls 13, earlier ones smooth, later ones strongly striate.”
Rhodina (?) mirabilis – “Alt. 24.5; diam. max. 3.5 millim.” (Sykes, 1902)
Type locality – “Kelantan, Malay Peninsula” leg. J. Waterstradt (Sykes, 1902)