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



sometimes rod-shaped and covered with thick spines, and sometimes spindle-shaped, 

 bearing small warts. They measure 0-33 by 0-05 ; 0-38 by 0-033 ; 0-3 by 0-034 : 0-38 

 by 0-08 ; 0-27 by 0-07 mm. The colour of the entire colony is bright coral-red. 



The species may be readily distinguished from Siphonogorgia mirahilis, which is the 

 one most nearly related to it, by the large spicules of the coenenchyma, which are visible 

 even to the unassisted eye. 



Habitat. — Amboina. 



Family III. Alcyonid^. 



Alyeonidse, Verrill, Proc. Essex Inst., vol. iv. p. 348, 1865. 



Alcyoninx retract iles, Klunzinger, Die Korallthiere des rothen Meeres, p. 21, 1877. 



The polyp colony is fleshy, forming sometimes a simple, at other times a more or less 

 branched, mass, of which there can often be distinguished a basal or stem-like portion, 

 sterile, and a capitular or head portion bearing the polyps. 



The thick coenenchyma surrounds the long polyp tubes, which are interconnected by 

 a system of fine nutrient canals. The pol}^s are retractile within well-marked depressions 

 in the coenenchyma. 



The polj^ps are sometimes dimorphic, the autozooids being for the most part sexual, 

 with well-developed tentacles, the siphonozooids being rudimentary, but in some cases 

 {Anthotnastus) also sexual. 



The spicules of the stem or sterile portion, when such exists, are larger, and often 

 different in form from those of the capitular portion. The capitulum, when present, is 

 mushroom-shaped or lobular. 



Species of the following genera were found during the voyage : — 



Bellonella, Gray. 

 Alcyonium, L. 

 Sarcophytum, Lesson. 



Lobophytum, Marenz. 

 Anthomastus, Verrill. 



Genus Alcyonium, Linn. 



Alcyonium, Linn., Syst. Nat., ed. x. p. 803 (pars). 



„ Milne-Edwards, Hist. Nat. des Coralliaires, t. i. p. 114 (pars). 



„ Klunzinger, Die Korallthiere des rothen Meeres, p. 21 {pars). 



We venture, though in opposition to the views of Klunzinger and others, only to 

 include in this genus those fleshy Alcyonids found in the temperate and cold seas, referring 

 those found in the tropics to the genus Lobularia. 



The genus may be known by the fleshy consistency of the colony, the large size of 

 the polyps, and the spindle-shaped spicules, which are not very densely distributed in 

 the coenenchyma. 



