Pycnoptychia torrei (R. Arango, 1876)
Goniapex townsendi (P. Bartsch, 1906)
Trilamellaxis transitoria (C. de la Torre, 1911)
Urocoptis transparens (L. Pfeiffer)
Anoma tricolor L. Pfeiffer, 1852
Badiofaux trilamellata (L. Pfeiffer, 1864)
Badiofaux trilamellata tomasensis C. de la Torre & P. Bartsch,1972
Gongylostoma trimellata (L. Pfeiffer, 1864)
Pycnoptychia trina C. de la Torre & P. Bartsch,1972
Torrecoptis trincherasensis C. de la Torre & P. Bartsch,1972
Microceramus trinidadensis C. de la Torre & P. Bartsch,1972
Brachypodella trinitaria (L. Pfeiffer, 1860)
Liocallonia triplicata (R. Arango, 1882)
Amphicosmia truncatula (J.B.P.A. Lamarck, 1822)
Bostrichocentrum tryoni (L. Pfeiffer, 1867)
Centralia tuba (C. de la Torre, 1911)
Tomelasmus tumidiorus (G.B. Sowerby, 1875)
Brachypodella tumidula W.J. Clench & C.G. Aguayo,1957
Brachypodella turcasiana (J. Gundlachin L. Pfeiffer, 1859)
Centralia turgida (C. de la Torre, 1911)
Centralia turgida doloresensis C. de la Torre & P. Bartsch,1972
Centralia turgida guajacoensis C. de la Torre & P. Bartsch,1972
Cochlodinella turiguanoensis C. de la Torre & P. Bartsch,1972
Gongylostomella turneri (H.A. Pilsbry, 1930)
Microceramus turricula (L. Pfeiffer, 1839)
Coelocentrum turris (L. Pfeiffer, 1856)
Coelocentrum tyla F.G. Thompson, 1968
Idiostemma uncata (L. Pfeiffer, 1859)
Torrecoptis unctuella C. de la Torre & P. Bartsch,1972
Uncinicoptis unguiculata (R. Arango, 1880)
Macroceramus unicarinatus (J.B.P.A. Lamarck, 1822)
Macroceramus utriculus C. de la Torre & P. Bartsch,1972
Spiroceramus vanattai W.J. Clench
Macroceramus vanattai H.A. Pilsbry, 1930
Spartocentrum vanduzeei G.D. Hanna, 1923