69 



Dendronephthya arakanensis, Henderson. 



A large specimen measuring 8 cm. in total height and about 6 cm. in 

 greatest width. 



The stalk is thick and flabby, and about 3"o cm. long; it is granular in 

 appearance and shows slight traces of stolons at the base ; its upper portion 

 is hidden by reflexed flattened branches. 



The polyparium is regular in outline, oval in shape and greatly flattened 

 in one plane. It is compact in appearance and has an almost unbroken surface, 

 the numerous branches standing in close contact with one another. Several 

 large branches are given ott' in the plane of flattening, arranged in pairs on 

 opposite sides of the stem. The two lowest branches are flattened, leaf-like 

 structures which i)ractically surround the stem ; they are reflexed and com- 

 pletely hide the uppermost third of the stalk. From the upper surface of each 

 and partly from the stem a large ordinary branch is given off'. All over the 

 surface of the stem and larger branches small secondary branches are given off 

 which by repeated division give rise to the polyp-bearing twigs. 



The polyps are arranged in small bundles of five to ten, seven and eight 

 being most usually met with, and may 

 occur singly or in small groups on the 

 edges of the flattened branches. They 

 are roiindish, 048 mm. high, 0"64 mm. 

 broad, and are placed almost at right 

 angles on the long stalks which mea- 

 sure about 1'2 nun. The spicules are 

 arranged in the following manner : At 

 the base of the polyp there are one to 

 two pairs of converging spicules ; then 

 there is a ring of horizontal spicules 

 about three deep, and above this rise 

 eight points in each of which there is 

 one pair of large spicules, one being 

 slightly longer than the other and 

 projecting ; occasionally a third spic- 

 ule is found lying alongside one of 

 this jtair. The lowei' polyp-spicules 



average 0-22 mm. in length, the upper 04 mm. They are spindles with regu- 

 larly arranged spines which on the projecting part are directed obliquely to- 

 wards the tip. On the aboral surface of the tentacles there are two rows of 

 small rod-like .spicules. 



The Stiitzbundel is Avell develoijed, and consists of a numlier of spicules 

 one of which may reach a length of 12 mm. and project a distance of 06 mm. 



Fig. 36. D. arakanensis. 



