Distansescharella alcicornis ( Jullien, 1882 ) López-Fé, 2006

López-Fé, C. M., 2006, Some bathyal cheilostome Bryozoa (Bryozoa, Cheilostomata) from the Canary Islands (Spain, Eastern Atlantic), with descriptions of three new species, a new genus, and a new family, Journal of Natural History 40 (29 - 31), pp. 1801-1812 : 1807

Distansescharella alcicornis ( Jullien, 1882) comb. nov.

( Figures 7 , 8 ; Table III)

Cribrilina alcicornis Jullien 1882 ; Harmelin 1978; Harmelin et al. 1989.

Material

Numerous colonies, with ovicells and ancestrulae, in both ‘‘ Madrepora 1’’ ( MNCN 25.03/ 3732) and ‘‘ Madrepora 2’’ ( MNCN 25.03/3737). Figured material, from ‘‘ Madrepora 1’’: MNCN 25.03/3723.

Descriptions

See Harmelin (1978) and Harmelin et al. (1989).

Remarks

Cribrilina alcicornis Jullien is a well-known species which does not need redescription. The numerous colonies present in the material from the Enmedio Volcan fit perfectly with previous descriptions ( Harmelin 1978; Harmelin et al. 1989), although autozooids are slightly larger than in colonies from more northern waters. However, this report considerably enlarges the known geographical limits of the species, not previously cited southwards from the Straits of Gibraltar ( Harmelin 1978; Harmelin et al. 1989). Otherwise, the depth of collection is within the previously known range of this bathyal species.

Assigning Cribrilina alcicornis to the genus Distansescharella d’Orbigny follows the opinion of Harmelin et al. (1989), who suggested that Distansescharella seguenzai Cipolla and Cribrilina alcicornis could be congeneric, although they did not formally propose the new binomen. After the clarification of Cribrilina Jullien by Bishop (1986, 1994), Cribrilina alcicornis cannot be retained in this genus, whose avicularia, when they exist, are adventitious and located at the sides of the orifice.

Harmelin et al. (1989) based their suggestion of a generic affinity between Distansescharella seguenzai and Cribrilina alcicornis on the similarity of the frontal shield, ovicell, number of spines, and the shape of the avicularia and the ancestrula. In both cases, the avicularia are vicarious. The zooids of D. seguenzai are linked by short tubules, and an alternation of kenozooids and avicularia separate the autozooids. Distansescharella alcicornis only occasionally has kenozooids, occupying spaces which leave no room for an autozooid. In addition, the zooids of D. alcicornis are united by dietellae in their walls, not by tubules. With these features, D. alcicornis is even more similar than D. seguenzai to the type species Distansescharella familiaris (von Hagenow) , which lacks kenozooids (except for filling occasional small spaces) and is not disjunct. Distansescharella familiaris was redescribed, and a neotype was chosen, by Voigt (1959), and was also discussed and figured by Harmelin et al. (1989). Both D. seguenzai and D. alcicornis lack the large spatulate avicularia of D. familiaris , but as Harmelin et al. (1989) proposed, this may be a specific character of the type species.

Figures

Figures 4–7. Copidozoum magnum sp. n.: (4–6) holotype (MNCN 25.03/3723); (7) paratype (MNCN 25.03/ 3723). (4) Autozooids, ovicells, and avicularia. (5) Avicularium. (6) Broken ovicell, with the basal kenozooid below. (7) Ancestrula (a) and first zooids, the small ancestrula at right (C.a.) belongs to Distansescharella alcicornis.

Figures 8–13. (8) Distansescharella alcicornis (MNCN 25.03/3723). (9–13) Acorania enmediensis gen. et sp. nov.: (9–12) holotype (MNCN 25.03/3726); (13) paratype 1 (MNCN 25.03/3727). (9) Autozooid with ovicell and avicularia, the broken ovicell at right shows the unfused endooecium and ectooecium. (10) Growing tip of a branch. (11) Uniporous chamber, distal side, with pore and limit of the chamber (arrow). (12) Inner side of the frontal wall, with condyles. (13) Ancestrula and first zooids.