Pachycleithonia Canu & Bassler, 1930

Type species: Pachycleithonia nigra Canu & Bassler, 1930

The genus Pachycleithonia nigra is now considered to be a junior synonym of Watersipora (Vieira, Spencer Jones & Taylor, 2014.

This genus includes the species:

Pachycleithonia nigra Canu & Bassler, 1930 Recent E. Pacific
Pachycleithonia nigra
(Thanks to Dennis Gordon & Paul Taylor)

Harmer notebook - entry for Pachycleithonia

[Commment: Vieira et al (2014) have placed Pachycleithonia in synonymy with Watersipora. (PEB 20/11/2006)]

[Comment: Banta (1969) and Cook (1985) both examined the type material of P. nigra from the Galapagos, and confirmed the absence of ovicells and the 'watersiporid' orifice. Banta redefined P. nigra and distinguished it from Watersipora arcuata, which also is found at the Galapagos.
Osburn (1952: 472) placed P. nigra in synonymy with Watersipora cucullata - as "var. nigra". Soule (1961:47) and Soule & Soule (1964: 36) discussed it as Watersipora nigra. However, it appears that their material was actually Watersipora arcuata.
P. nigra is certainly a watersiporid, but the two other species referred to the genus have ovicells, and appear to be distinct (PLC 17/01/2005)]

[Comment: Pachycleithonia mutabilis (Now Nigapercula mutabilis) was introduced as Galeopsis mutabilis (Canu & Bassler 1929: 273). Material listed as 'Cotypes' (USNM 8024, 8025) was from two localities - D5141 and D5144, but these appear to be distinct forms. Specimen D5144 (Plate 28 fig. 4, 5) shows ovicells (worn) and a "spiramen". Plate 28 fig. 6 (Specimen D5141) is illustrated with a retouched photograph showing acute lateral oral avicularia. These do not exist in the specimen, and avicularia should be deleted from the species definition.
Harmer (1957) and Cook (1985) have examined part of the type material and noted that there are no avicularia. Cheetham (in litt.) also observed that the specimens have areolae, not avicularia.
Harmer (1957) examined fragmentary material from the Siboga expedition, and a colony from the Mascarene Islands, which was figured by Hayward & Cook (1983) as P. mutabilis. (PLC 17/01/2005)]

[Comment: Cook (1968) first suggested that other species may be referable to Pachycleithonia. Hayward & Cook (1983) referred Galeopsis mutabilis to Pachycleithonia, and mentioned P. africana, which is a nomen nudum. The reference "Cook 1983b" was not published until 1985.
"P." africana (Now Nigapercula africana) and "P." mutabilis have similar ovicells, but the ovicell of P. africana is closed by the operculum, while this is not the case in P. mutabilis. (PLC 17/01/2005)]

[Commment: The "two other species" are now included in the new genus Nigrapercula" (PEB 20/11/2006)]


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Edited by Phil Bock
Modified on 15th April 2005
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