From editor or global species database
Type species The designation of the type species of Thracia is not straightforward. There are two originally included names with the description by Blainville (1824), his own T. corbuloidea and T. pubescens Leach, but at that time T. corbuloidea is still a nomen nudum, not available nomenclaturally, and Leach did not publish the name pubescens which is however available from Pulteney, 1799.
Later Blainville (1827, p. 660, in corrections and additions to his "Manuel de Malacologie") stated that Thracia pubescens should be excluded but ICZN art. 69.4. says that "Elimination of all but one of the originally included nominal species from a nominal genus or subgenus does not in itself constitute type fixation"
The first formal fixation comes in Deshayes (1830) in the entry for Thracia of "Dictionnaire classique d'histoire naturelle" vol. 16, where he writes "C'est de cette manière que nous avons su que cette belle espèce [Thracia pubescens] était devenue le type d'un nouveau genre du zoologiste anglais. "
However he also describes Thracia pubescens as new species, based on a specimen in Brongniart collection with a manuscript label by Leach, which makes it separately available, homonymous and synonymous with Thracia pubescens Pulteney also based on Leach's unpublished name.