Prionitis lanceolata (Harvey) Harvey var. angusta Harvey, 1853: 197–198 (type locality: San Francisco, California, U.S.A.).
Prionitis angusta (Harvey) Setchell in Collins, Holden, & Setchell, 1899 [1895–1919]: fasc. A: no. XXIV, nom. illeg.
Prionitis filiformis Kylin, 1941: 13.—Papenfuss, 1968b: 279–280.— Seagrief, 1977: 90.— Seagrief, 1988: 54, fig. 5:9.— R. Anderson & Stegenga, 1989: 304.
INDIAN OCEAN DISTRIBUTION: South Africa.
Note: Prionitis filiformis is a substitute name for P. angusta (Harvey) Setchell, published July 1899, a later homonym of P. angusta (Okamura) Okamura (1899: 4), published 20 January 1899. The latter name was intended to be a new combination of Gymnogongrus ligulatus Harvey var. angustus Harvey (1860a: 332; intended type locality: Shimoda, Japan), but this varietal name is invalid because the specific name was invalid at that time (see Art. 43.1). Gymnogongrus ligulatus was proposed as a new species by Harvey in his Ceylon exsiccata (1857a: no. 50), but no description was provided. The name was validated by Kützing (1869: 23–24, pl. 63: figs. a, b). Harvey's varietal epithet was validated by Okamura as Cryptonemia angusta Okamura (1895: 478, pl. IX: figs. 8–15). Thus, the authorship of the Japanese Prionitis angusta is (Okamura) Okamura, not (Harvey) Okamura as usually cited.