2 THE A^OYAGE OF H.M.S. CHALLENGER. 



without spicules, at other times with numerous transparent glassy, fusiform, often 

 spiny spicules, or with irregular scale-like spicules ; sometimes the spicules are in two 

 layers. Polyps ; large, prominent, inserted on the axis either at right angles or 

 obliquely ; covered with spicules, variously arranged ; tentacles retractile, sometimes only 

 imperfectly so. 



1. Strophogorgina3. — Simple unbranched axis. 



2. Chrysogorginae. — Branched axis. 



Subfamily 1. Strophogorgin^. 



Colony unbranched. The axis consists of a simple, calcareous, often brittle stem, 

 springing from a number of root-like processes ; sometimes erect, rigid, round ; sometimes 

 trailing. The coenenchyma ; in some extremely thin, allowing the iridescent axis to 

 be seen through it, and furnished with few spicules ; at other times it is thick and 

 membranous, with numerous spicules. Polyps ; prominent and arranged in a uniserial 

 manner on the axis. The tentacles are retractile, forming by their basal portions 

 quasi-opercular coverings. The polyp bodies are covered with spicules, which are often 

 arranged towards the apices of the potyps in eight rows, eventually becoming smaller and 

 then beins; lost on the extremities of the dorsal surflice of the tentacles. 



The spicules are translucent glass-like spindles or scales of irregular form ; the spindles 

 are sometimes smooth ; sometimes with roughened edges. 



Genus Strophogorgia,^ Perceval Wright. 

 Stropliogorgla, Perceval Wright, Narr. Cliall. Exp., vol. i. pt. ii. p. 691, 1885. 



Colony unbranched ; axis calcareous, erect or creeping ; iridescent. Base whei'e 

 observed, calcareous, divided into diverging hard and Ijrittle root-like stractures for 

 anchoring the colony in the mud. 



The polyps are prominent and arranged in a uniserial manner on the axis, either 

 stalked or sessile. The coenenchyma varies in thickness, being sometimes very thin, with 

 few spicules ; or membranous, with numerous spicules. 



Four species are found in the collection. 



I. Strophogorgia petersi, n. sp. (PL IT. figs. 1, 1« ; PI. Va. fig. 1). 



Colony simple, unbranched. Axis calcareous, brittle, in some specimens exceeding 

 6 dm. in length ; the basal portions with numerous, broad, rhizome-like processes, 

 from 3 mm. in diameter at the base to less than 1 mm, at tJicir apices. 



