ALCYONARIAN CORALS 



12^ 



very short. The coenenchym covering the branches is very 

 thin (Fig. 55). 



There is a passage in Phn^^'s Natural History, viii. cap. 

 52, which has given rise to some controversy. It may be 

 translated, " Juba states that 

 about the islands of the Troglo- 

 dytes there is a shrub found out 

 at sea called the ' Hair of Isis.' " 

 It is very unlikely that such a 

 name would have been given to 

 the coral now called Isis hippuris ; 

 but it may have been given to the 

 beautiful and delicate Isidella from 

 the Mediterranean Sea in the first 

 instance, and the same name given 

 at a later period to Isis liippiiris 

 on account of its similarly jointed 

 axis. 



Melitodes. — In many regions 

 of the tropical seas there may be 

 found some very brightly coloured 

 flexible corals which might, at first 

 sight, be attributed to the family 

 Isidae, as they also exhibit a " con- 

 trivance " of alternate nodes and 

 internodes in the axis. Many of 

 these belong to the genus Melitodes. 

 A critical examination of the axis 

 shows that it is quite differently 

 constructed from the axis of Isis, 

 for, instead of being solid, both 

 nodes and internodes are perforated 

 by canals, and for this reason the 



genus and its allies are placed in a separate family — the 

 Melitodidae. The largest and probably the commonest of 

 these is the species Melitodes ochracea, known to the older 

 writers as the Red King Coral. 



The colour is very variable, as it is in all the species of 

 the genus, and may be either uniformly dark red or dark 



Fig. 56. — Wnghtdla robitsta 

 from Singapore. The genus 

 Wrightella is closely related to 

 ;\Ielitodes. Nat. size. After 

 Shann, Proc. Zool. Soc, 1912, 

 PI. LXII. 



