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



Family Plexaurid^;, Gray. 



Eunicea, Lamouroux. 



Eunicea, Lamouroux, Hist, des Polyp, flexibl., p. 431, 1816. 

 ,, Milne-Edwards, Hist. Nat. des Coralliaires, t. i. p. 146. 



Eunicea palmata, n. sp. (PI. IV. figs. 2a, 2b ; PI. V. fig. 9). 



Colony upright ; slightly branched in one plane, the branches commencing about 

 halfway up the stem. A thick cylindrical stem rises from a broad leaf-like base to a 

 height of 330 mm.; thickness at the base 9 mm., near the apex 6 mm. Its course is 

 irregularly curved. The first branches are given off at a height of 100 mm.; these are 

 few and thick, and arise from both sides at right or obtuse angles. They bend upwards 

 after a short distance, and take a course parallel to that of the stem; The lower ones are 

 large, giving off two or three long twigs with the same characters as the branches. 

 The upper ones are but short, and stand straight out. Branches and twigs are 

 thick, cylindrical ; some bend downwards gradually towards the base, thickened ter- 

 minally. The branches average 190 mm. in length, with a thickness at the base of 

 7 mm. and of 6 or 7 mm. near the tip. The simple side twigs are 50 to 120 mm. long. 

 The ccenenchynia which covers stem and branches is thick and full of spicules. In a 

 branch 6 mm. in diameter it averages 2 mm. in thickness. The polyps are distributed 

 over the whole surface, and quincuncially arranged ; generally they appear at 

 intervals of 2 mm. apart, and only at the ends of the twigs are they more closely 

 disposed, so that the walls of the calyces are in contact. The apex is occupied by a 

 single polyp calyx. Each polyp is formed by a calyx and a completely retractile oral 

 region over which the calyx mouth may be completely closed as a two-lipped slit. 



The calyces are low ; on the stem and on the lower part of the branches they project 

 but slightly, and are wart-shaped. Towards the ends of the branches and twigs they are 

 higher. Their height is 1 to 2 mm., their diameter 2 to 2"5 mm. 



The spicules of the ccenenchyma and of the calyces are mostly club-shaped. Straight 

 and bent clubs with more or less leaf-like ends may be distinguished ; they are covered 

 with rough warts, or with branched, curved, and straight processes. Dimensions - 38 

 by 0'1 mm.; 0"5 by - 12 mm.; 0'4 by 0'09 mm. In addition, there occur straight 

 and bent spindles with warts and spines, or with irregular processes which may be 

 branched ; these exhibit manifold transitions towards the club-shaped form. Dimen- 

 sions 0-35 by 0-05 mm.; 0"5 by 0"05 mm.; 0"43 by 0-07 mm.; 0-33 by 0'05 mm. 



