Phosinella redferni (Espinosa and Ortea, 2002)

Phosinella cancellina (Rolán and Fernández-Garcés, 2010)

Phosinella redferni (Espinosa and Ortea, 2002)

Phosinella cancellina (Rolán and Fernández-Garcés, 2010)

"Xeno Beach," Tarpum Bay, Eleuthera, Bahamas (5.7 mm.)

    Drift in sand pockets of the "iron shore," SW Grand Cayman Island at Sunset House. February, 1970 (7.00 mm.)

Phosinella pulchra (C. B. Adams, 1850)

Phosinella sagraiana (d’Orbigny, 1842) Sagra’s Risso

Phosinella sagraiana (d’Orbigny, 1842) Sagra’s Risso

    Store Bay, Tobago Island, Republic of Trinidad and Tobago, dredged 200-230 feet. May, 2004 (4.6 mm.)     In shell grit taken by SCUBA from a depth of 69 feet off Boynton Beach, FL  (4.3 mm.)

Phosinella fenestrata (Schwartz, 1860)

 

Phosinella fenestrata (Schwartz, 1860)

 
    Collected at Rancho Luna, Cienfuegos, Cuba by the photographer, Raúl Fernández-Garcés (3.4 mm.)  
Phosinella labrosa (Schwartz, 1860) Phosinella species (Leal, 1991: pl. 9, figs. A, B)

Phosinella labrosa (Schwartz, 1860)

Phosinella species (Leal, 1991: pl. 0, figs. A, B)

    In Rubble, 1 to 4 feet, in front of Trudy's Hotel, E end of Utila Island, (Caribbean) Honduras. B. Holiman! April, 1988 (8.0 mm.)     Dredged, 172 ft., Vitória Seamount, off SE Brazil. Bouchet, Leal, and Métivier! May, 1987 (6.0 mm).

Digital images by David Kirsh

Comments by Harry G. Lee

    Early in August, 2010, I came to the conclusion that Phosinella pulchra (C.B. Adams, 1850: 114), as interpreted by Redfern (2001: 34; plate 17, fig. 141), was a distinct biotaxon. A close look at the uncharacteristically well-preserved holotype, including its protoconch (Clench and Turner, 1950: plate 33, fig. 8) confirms Redfern's identification and places its synonymy with P. cancellata (Philippi, 1847), as asserted by Desjardin (1949: 204) and Ponder (1985: 83) in serious doubt. Since the C.B. Adams taxon is the type of Phosinella Mřrch, 1876; see http://bhl.ala.org.au/item/53851#page/73/mode/1up (subsequent designation by Nevill, 1885: 73, 83),** this is no small taxonomic matter.

    Delving further, I found that the figures of "Rissoina (Phosinella) cancellata Philippi" in Ponder (1985: plate 135, figs. A and B) were not consistent with Redfern's clearly-expressed concept of that taxon but  fit that of his P. sagraiana (d'Orbigny, 1842); see Redfern (op. cit. 34; plate 17, figs. 140, 142, respectively) and above.

    Working independently Rolán and Fernández-Garcés (2010) agreed with this assessment, but they took the research a bit further and located the holotype of R. cancellata at the Zoologische Museum, Berlin. This specimen is actually not at all the species Redfern described and figured; it is clearly synonymous with R. sagraiana. They considered Redfern's "R. cancellata" a theretofore unnamed species and dubbed it Rissoina cancellina (see above).

    An additional cloud over Adams' Rissoa pulchra was nomenclatorial: it is a primary junior homonym of Rissoa pulchra Forbes, 1844, and neither I nor Rolán and Fernández-Garcés (2010) could find a synonym to recruit into usage. However, those workers argued that the Forbes taxon was not identifiable and its name had been used much less frequently than R. pulchra C. B. Adams, 1850, so they proposed protecting its availability.

    Stepping back to a generic perspective, we can appreciate Phosinella in the western Atlantic includes the four taxa of Redfern (2001: plate 17, figs. 140-143): the three mentioned above and P. redferni (Espinosa and Ortea, 2002), which is based on the former author's Rissoina sp. B (Redfern, op. cit. 34, plate 17, figure 143); see above. To those we may add P. fenestrata (Schwartz, 1860) recently redescribed by
Rolán and Fernández-Garcés (2009), Phosinella labrosa (Schwartz, 1860), and Rissoina fenestrata of Leal (1991: 75-76; pl. 9, figs. A, B) not of Schwartz, 1860.

 



**
Two years later the type species was restricted to Rissoina sagraiana d’Orbigny, 1842 by Tryon (1887: 320; see http://tinyurl.com/443zyuh), but the die had been cast.

Adams, C.B., 1850. Descriptions of supposed new species of marine shells which inhabit Jamaica. Contributions to Conchology 7: 109-123. April. <http://www.archive.org/details/contributionstoc00adam>; <http://www.biodiversitylibrary.org/item/48996#page/124/mode/2up>

Clench, W.J. and R.D. Turner, 1950. The western Atlantic marine mollusks described by C. B. Adams. Occasional Papers on Molluscs 1(15): 233-403 incl. pls. 29-49. June 26.

Desjardin, M., 1949. Les Rissoina de l’île de Cuba. Journal de Conchyliologie 89(4): 193-208 + pls. 9-10.

Leal, J.H., 1991. Marine prosobranch gastropods from oceanic islands off Brazil. Backhuys, Oegstgeest, Netherlands. x + pp. 1-418 incl. 22 pls.

Mřrch, O.A.L., 1876. Synopsis molluscorum marinorum Indiarum occidentalium imprimis insularum danicarum. Malakozoologische Blätter 23: 45-58, 87-143.

Nevill, G. 1885. Hand list of Mollusca in the Indian Museum, Calcutta. Part II. Gastropoda. Protobranchia-Neurobranchia (cont'd.). Government Printer, Calcutta. x + 306 pp.

Ponder, W. F., 1985. A review of the genera of the Rissoidae (Mollusca: Mesogastropoda: Rissoacea).  Records of the Australian Museum supplement 4: 1-221.

Rolán, E. and R. Fernández-Garcés, 2009. New information on Cuban Rissoina (Mollusca: Rissoidae) 1. Rissoina fenestrata and R. vanderspoeli. Novapex 10(2): 59-64. 10 June.

Rolán, E. and R. Fernández-Garcés, 2010. New information on the Caribbean Rissoina (Gastropoda, Rissoidae) of the group R. sagraiana-cancellata, with the description of a new species. Iberus 28(1): 79-89.

Schwartz von Mohrenstern, G., 1860. Über de familie der Rissoiden insbesondere die gattung Rissoina. Denkschriften der Mathematisch-Naturwissenschraftlichen. Classe der Kaiserlichen Akademie der wissenschraften 169: 70-188, pl. 1-11.