Zospeum percostulatum sp. n. Frontal views of three paratype shells (A–C 1.41, 1.80, 1.58 mm) and a shell from Cueva Collubina (D 1.49 mm) [ZUPV]. Note the robust, smooth columella through the window opened in the body whorl (C) and closer, smaller riblets in D.

 
 
  Part of: Alonso A, Prieto CE, Quiñonero-Salgado S, Rolán E (2018) A morphological gap for Iberian Zospeum filled: Zospeum percostulatum sp. n. (Gastropoda, Eupulmonata, Carychiidae) a new species from Asturias (Spain). Subterranean Biology 25: 35-48. https://doi.org/10.3897/subtbiol.25.23364