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Two new species of Pyrgulopsis Call & Pilsbry, 1886 (Mollusca: Caenogastropoda: Hydrobiidae) from springs in the Rio Grande watershed in Texas

. Zootaxa. 5071, 3 (Nov. 2021), 384–402. DOI:https://doi.org/10.11646/zootaxa.5071.3.5.