STEUCTURE Or ISIS HIPPUBIS. 



431 



walls, are circular in section, and have a diameter in some cases 

 of about 1 millim. 



Tlie polyps (PL 43. fig. 4) are scattered over the whole coenen- 

 chyma at intervals of 0*5 to O'l millim. There are no verrucse; so 

 that when the anthocodise are withdrawn the surface presents a 

 dotted appearance. Eoundeachof the openings the spicules are 

 grouped in eight bundles, and so form a stellate figure. The 

 expanded polyp has a length of 1"25 millim. 



The tentacles are 0'5 millim. in length, with a diameter of 

 0'5 millim. at their base. They are flat and lanceolate, and 

 bear a single row of short, thick, cylindrical pinnules. They 

 are first infolded so as to form a somewhat elongated cone, and 

 then the whole is withdrawn within the level of the ccenenchyma. 

 The polyp-cavities (PI. 43. fig. 3) are vase-shaped, and have 

 a depth of 1"25 millim., with a maximum diameter of similar 

 dimensions. 



Spicules a~i : different types from the coeneucbyma. 



It is interesting to note that we have here another example of 

 viviparity among Alcyonaria. As Prof. Hickson notes (' Marine 

 Investigations in South Africa,' vol. i. (1902) p. 84), the occur- 

 rence of embryos has been recorded in Corallium rubrum 

 (Lacaze-Duthiers), some species of Clamdaria, Sympodium 

 (Alcyoniuni) coralloides (Marion and Kowalewsky) and in three 



31* 



