Euperisiphonia rigida Fraser, 1940a

Calder, Dale R. & Choong, Henry H. C., 2018, Names of hydroids (Cnidaria, Hydrozoa) established by Charles McLean Fraser (1872 - 1946), excluding those from Allan Hancock Expeditions, Zootaxa 4487 (1), pp. 1-83: 39

publication ID

publication LSID

persistent identifier

treatment provided by


scientific name

Euperisiphonia rigida Fraser, 1940a


Euperisiphonia rigida Fraser, 1940a 

Euperisiphonia rigida Fraser, 1940a: 579  , pl. 33, figs.7a –c.

Zygophylax rigida  .— Fraser 1944a: 232, pl. 44, figs. 197a –d.

Cryptolaria rigida  .— Rees & Vervoort, 1987: 51 [not Cryptolaria rigida ( Fraser, 1948)  ].

Holotype. USNM 43439View Materials: Mexico, Quintana Roo, Yucatan Channel, R/ V Albatross Sta. 2354, 20°59’30”N, 86°23’45”W, 238 m, 22 January 1885, small beam trawl; ethanol.GoogleMaps 

Type locality. Mexico: Yucatan Channel, 20°59’30”N, 86°23’45”W, 238 m ( Fraser 1940a).

Current status. Valid, as Cryptolaria rigida ( Fraser, 1940a)  .

Remarks. The only known type material of Euperisiphonia rigida  is in collections at the NMNH ( USNM 43439). Designated as the “ type ” by Fraser (1940a), it is recorded as a holotype in the NMNH online database. The collection was referred to as the “ type series” by Rees & Vervoort (1987). However, Fraser (1940a) remarked in describing the species that the “largest fragment”, presumably of a single damaged colony, was 3.5 cm high. The gonosome of the species has yet to be described. This specimen could not be located at the NMNH during a visit by one of us ( DRC) in September 2017.

Euperisiphonia rigida Fraser, 1940a  has been referred to Zygophylax Quelch, 1885  in some works (e.g., Fraser 1944a, b; Vervoort 1968) and to Cryptolaria Busk, 1857  in others (e.g., Rees & Vervoort 1987; Vervoort & Watson 2003). Its correct generic assignment is still somewhat debatable ( Vervoort & Watson 2003: 53), although the species is currently assigned to Cryptolaria  in WoRMS. Also thought referable to Cryptolaria  is Lictorella rigida Fraser, 1948  (Calder et al. 2009). Secondary homonymy arises when the two species are assigned to the same genus, whether Cryptolaria  , as C. rigida ( Fraser, 1940a)  and C. rigida ( Fraser, 1948)  , or Zygophylax  , as Z. rigida ( Fraser, 1940a)  and Z. rigida ( Fraser, 1948)  . To minimize potential nomenclatural confusion over the two, and see Schuchert (2015: 331), a replacement name is proposed here for the junior secondary homonym C. rigida ( Fraser, 1948)  . That name, Cryptolaria crassa  , nom. nov. (Latin crassus, thick, strong), refers to the thick and rigid hydrocaulus of the species.


Smithsonian Institution, National Museum of Natural History


Smithsonian Institution, National Museum of Natural History














Euperisiphonia rigida Fraser, 1940a

Calder, Dale R. & Choong, Henry H. C. 2018

Euperisiphonia rigida

Fraser, 1940a : 579

Zygophylax rigida

Fraser 1944a : 232

Cryptolaria rigida

Rees & Vervoort, 1987 : 51