Systematic discussion of genera and species. 



Acanthogorgia Gray (emended by Verrill). 



Acanthogorgia Gray. Proceedings Zoological Society of London, 1857, p. 128. 

 Acanthogorgia (including Bleplirogorgia Duchassaing et Michelotti) Verrill. Memoirs Museum 



of Comparative Zoology, XI, I, p. 30, 1883. 

 Acanthogorgia Wright and Studer. Challenger Report, Alcyonaria, 1889, p. 93. 



Calyces tubular, their walls with spindles arranged en chevron, and their margins 

 surmounted by a crown of thorns which are sometimes single and sometimes in a cluster. Each 

 of these marginal spicules is a bent spindle with a tuberculate base embedded in the caly.x 

 wall and a thorn-like, comparatively smooth distal portion projecting from the calyx margin. 

 Other similar spicules may occur in the walls below the margin, and spicules of various types 

 in the coenenchyma of the stem and branches. 



The characteristic spicules described above constitute the Acanthogorgia type. In the 

 species of this genus the bent spindle predominates, although several other types, such as 

 crosses and triradiate spicules, are found in some species. 



The disposition of the spicules en chevron in the calycular walls is also a very good 

 generic character, shared, however, with the genus Paratmiricca. This latter genus differs from 

 Acanthogorgia in not having the Acanthogorgia type of spicules. 



The type species of this genus is Acanthogorgia hirsnta Gray^ 



The genus as thus defined would include the following species ; — Acanthogorgia 

 ceylo7iensis Thomson and Henderson, A. aspera Verrill, A. flabelhtni Hiles, A. hirsnta Gray, 

 A. horrida Studer, A. inermis Hedlund, A. laxa Wright and Studer, A. longiflora Wright 

 and Studer, A. media Thomson and Henderson, A. muricata Verrill, A. ramossissima Wright 

 and Studer, A. riV/^j)'/ Wright and Studer, A. .rt/;r<zw/;2z (Duchassaing et Michelotti), A. spinosa 

 Hiles, A. truncata Studer and A. verrilli Studer". To these are added the new species from 

 the Siboga collection described beyond. 



I. Acanthogorgia ridleyi Wright and Studer. 



Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 95. 

 ROULE. Resultats scientifiques de la Campagne du "Caudan", 1896, p. 306. 



Stat. 5. 7°46' S., 1 14° 30'. 5 E. Madura Sea. 330 meters. Coral and stones. 

 Stat. 212. 5°4s'.5 S., I20°I9'.2E. Banda Sea. 462 meters. Fine grey mud. 

 Stat. 259. 5°29'.2S., 1 32° 52.5 E. near Kei Islands. 487 meters. Coral sand. 



Colony straggling in habit, 16 cm. in height. The main stem divides about i cm. from 

 its origin into two long, straggling branches, one of which gives off three short branchlets from 

 its pro.ximal portion, its distal half being unbranched. The other branch gives off four side 

 branches, its distal half being almost unbranched. The coenenchyma is fairly thick for this genus. 



' Gray. Proceedings Zool. Soc. London, 1857, p. 128. 



2 Papers received since the above was written show that the following should be added to this list: A. Candida Kiikih., 

 A. gracillima Kiikth., A. spina Kükth., A. japonica Kiikth., A. dofleini Kükth., A. angustifiora Kiikth. and A. multispinosa Kiikth, 



