118 THE VOYAGE OF H.M.S. CHALLENGER. 



The axis is horny, feebly flexible, as in the former species, and of a yellow-brown 

 colour. The colour of the stem, in spirit specimens, is whitish. 

 Habitat. — Kaudavu Reef, Fiji. 



Genus 10. Echinogorgia, Kolliker. 



Echinogorijia, Kolliker, Icones Histiologicn?, vol. i. p. 13C, 1856. 



Professor Kolliker separated this genus from Muricea, and characterised it as 

 consisting of " Primnoids with a horny axis, with small spiny spicules of a peculiar 

 form ; and polyps scarcely at all prominent." KoUiker places in this genus Esper's 

 Gorgonia sassapo, Gorgonia wnhratica, Gorgonia purpuracea, and Gorgonia cerea. 

 Gorgonia sassapo, var. reticulata, Esper, is also included under the new name of 

 Echinogorgia pseudosassapo, KoU. 



Verrill, in his Notes on Radiata,^ adds also to these species Leptogorgia aurantiaca, 

 Milne-Edwards, from Callao. A new species, Echinogorgia intermedia, Studer, is 

 described by Studer in the Alcyonaria of the voyage of the " Gazelle."^ Lastly, Ridley 

 thinks^ that Antipathes JlaheUum, 'Es,^., — Gorgonia cancellata, Dana, should be placed 

 in the genus, an opinion in which we concur. 



All the above-enumerated eight species, with the exception of Echinogorgia cmran- 

 tiaca, have been examined by us ; all present upright colonies, for the most part 

 branched in one plane. The branches are either free or anastomosing into a network. 

 The axis is horny, sometimes flattened. The coenenchyma is thick, not transparent. 

 The polyps are small, but slightly prominent, papilliform, and usually in close spirals 

 surrounding the stem. The operculum is, for the most part, feebly developed, and is 

 sunk wdthin the margin of the polyp calyx, over which it does not project. It is 

 formed by two or three spicules at the base of each of the tentacles. The spicules of 

 the ccBnenchyma and of the polyps are very numerous. KolUker describes them as 

 unilateral spiny spindles, one-sided spiny clubs, echinulate discs, warty spindles, and 

 double stars. Besides, there are also peculiarly formed " Blattkeulen," whose dentate 

 folia project beyond the coenenchyma, and give it a roughened prickly appearance. In 

 the diflferent species, sometimes one and sometimes another form of these spicules will 

 be found to predominate. In those with a well-developed coenenchyma, where the 

 polyps are somewhat apart from one another, the one-sided spiny spindles predominate ; 

 while in others, with closely packed polyps, the " Blattkeulen " or the spiny discs are 

 present. The axis is always horny and frequently compressed. All the species at 

 present known belong to the Indo-Pacific Seas. 



Two species were in the Challenger collection. 



> Trans. Connect. Acad., vol. i. pt. ii. p. 418. " Monatsber. d. l-.jweuss. Akad.d. Wiss. Berlin, October 1878, p. 651. 



3 Zool. Coll. H.M.S. "Alert," p. 337. 



