36 



Fam. Alcvonidiidak Johnston. 



Alcyonidiêes (part) Lamouroux, 1813, Ann. Mus. Hist. Nat. XX, p. 2S4. 

 Alcyonidulae Johnston, 1838, "Hist. Brit. Zooph.", Ed. i, p. 300. 

 Alcyonidulae Couch, 1844, "Cornish Fauna", III, p. 132. 

 Alcyonidiadae Johnston, 1837, Trans. Benvicksh. Nat. Club, I, p. 108. 

 Alcyonidiadae Gray, 1848, "List Brit. An. Brit. Mus.", I, pp, 91, 144. 

 Alcyonidiidae Hincks, 1S80, "Hist. Brit. Mar. Pol.", p. 490. 



Alcyonidium Lamx. 



Alcyonidium Lamouroux, 1813, "Essai Gen. Thalassiophytes" (Suite). Ann. Mus. Hist. Nat. 



(Paris) XX, p. 285. 

 Alcyonidium Lamouroux, 1821, "Exp. Méthod.", p. 71. 



Alcyonidium was introduced by Lamouroux (18 13) as a genus of Sea-weeds. The genotype 

 is A. diaphanum = A. gelatinosum L. 



No specimens of Alcyonidium have been found among the 'Siboga' dredgings; but I 

 include the genus in the present Report on the evidence of a single specimen from Torres Straits. 



As Waters l ) has pointed out, Alcyonidium has rarely been recorded from the Southern 

 Hemisphere. Besides A. antarcticum, described in the Memoir here referred to, Waters mentions 

 A. Jïaöclliforme Kirkpatrick, 1902 (Antarctic), A. flustroides Busk, 1886 (Cape of Good Hope) 

 and A. gelatinosuni, mentioned by Hincks 2 ) as having been found off the coast of Natal. In 

 the absence of any evidence on the subject, some doubt may be expressed with regard to the 

 correctness of the last determination. To the list given by Waters may, however, be added 

 A. mytili, recorded by Kirkpatrick (1888) from Victoria and A. mytili Calvet from Tierra 

 del Fuego. From Oriental waters Miss Thornely has given A. mytili as occurring in the Gulf 

 of Manaar. These records are quoted in the subjoined synonymy. From the Northern Pacific 

 Miss Robertson 3 ) has described four species of the genus, three of which are determined as 

 belonging to British species. In a later paper + ) the same author has described another species, 

 A. pedunculatum, besides giving a new description of the remarkable Ascorhiza occidentalis 

 Fewkes, 1889, also referred to the Alcyonidiidae. It has, however, been pointed out by Waters ') 

 that Ascoi'hiza is synonymous with Clavopora^ described by Busk ü ) in 1874 from the dredgings 

 of the 'Porcupine' in the Mediterranean, in deep water off the African coast. 



It may be concluded from these facts that the Alcyonidiidae are mainly Northern forms, 

 and specially Atlantic. In other parts of the world they would appear to be most common in 

 the North Pacific. As the genus Alcyonidium extends into high latitudes in the Atlantic area, 

 its occurrence elsewhere may have been due to its invasion of the Pacific from the North. 



il WATERS, A. W., 1904, "Kés. Belgica", "Bryozoa", p. 86; see also 1904, Min. Fr.-Josef Land", II, J. Linn. Soc. Zool., 

 XX1N, p. 178. 



2) Hincks, T., 1880, p. 492. 



3) Robertsox, A., 1900, "Harriman Alaska Exp.", "Bryozoa", Proc. Washington Acad. Sci.. II, pp. 329, 330. 



4) Ibid., 1902, "Obs. on Ascorhiza.. and Related Alcyonidia", Proc. Calif. Acad. Sci., (3) Zool., III, pp. 104 — 



5) Waters, A. W., 1910, p. 240. 



6) BüSK, <... 1874, "C/avopora hystricis", Quart. J. Mier. Sci., (N. S.) XIV, p. 261. 



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