Potamobius Hope, 1838

Gustafson, Grey T. & Miller, Kelly B., 2013, On the family- and genus-series nomina in Gyrinidae Latreille, 1810 (Coleoptera, Adephaga), Zootaxa 3731 (1), pp. 77-105 : 98

Potamobius Hope, 1838

The generic nomen Potamobius Hope, 1838 raises a nomenclatural problem. Hope (1838) presented a table of the genera of GYRINIDAE and listed Potamobius credited to Leach, with the type species P. modeerii Marsham, 1802 . In accordance with Article 12.2.5 of the Code, Hope’s table with clear indication to the valid species of “ modeerii Marsham ” is an indication. Marsham’s (1802) nomen was actually originally Gyrinus modeeri , and Hope (1838) seems to have simply misspelled it.

Hope’s (1838) table includes brackets around genera considered to be synonymous. He considered Orectochilus (which he spelled Orectocheilus ) as a synonym of Potamobius , and stated in his discussion of Orectochilus villosus that the species is “Now a Potamobius of Leach”. Hope’s (1838) statement gains additional meaning upon reading Stephens’ (1829a) section on GYRINIDAE . Stephens (1829a) listed references in parentheses including the author followed by a citation. A source frequently cited is “(Sam. I. 20)” clearly referring to Samouelle (1819). Stephens (1829 a) presented two divisions for the species of GYRINIDAE , “A. Elytris glabris” and “B. Elytris villosis.—( Potamobius, Leach MSS. )”, the latter including species “543. 7, villosus ” with “ Gy. Modeeri Marsham” apparently listed as a synonym. Samouelle (1819) presented a similar arrangement for the GYRINIDAE with the divisions “’* Elytra naked, with punctured striae.’ Leach.” and “** Elytra smooth, villose.’ Leach”. Samouelle (1819) acknowledged that Leach had given him all of his manuscripts for use in his work and he credited Leach for those ideas, including the nomen Potamobius . Hope (1838) was apparently under the impression that Stephens (1829 a) placed the species O. villosus as well as G. modeeri into the genus Potamobius based on Leach’s unpublished manuscript, though that was not clearly Stephens’ (1829 a) intention. Additional evidence that Stephens (1829 a) was merely citing Leach’s manuscript comes from another of his papers published the same year (Stephens 1829 b) in which he included only a single genus in the GYRINIDAE , Gyrinus , including the species G. villosus , suggesting that he did not recognize Potamobius as a valid nomen.

The nomen Potamobius was used again for a genus by Samouelle (1819), attributed again to Leach, but for a crustacean, having nothing to do with the GYRINIDAE . This, however, makes Potamobius , as conceived by Hope (1838) for the GYRINIDAE , a junior homonym of Potamobius Samouelle, 1819 . The type listed for Potamobius by Hope is “ modeeri ”, which by most authors is considered a junior synonym of O. villosus Müller , making Potamobius Hope, 1838 both a junior homonym and a junior subjective synonym.