FROM THE INDIAN AND PACIFIC OCEANS. 

 Spicule-measurements in mm. 



31 



Fam. Siphonogoegioj! (Kiikenthal). 



Tliis family contains the two genera Siphonogorgia and Chironephthya, distinguished 

 by the following diagnostic characters : — 



Genus Siphonogorgia. 

 Stiff branching Siphonogorgiidae, with smooth, round, cylindrical stem and branches, 

 having one main central nutritive canal in the stem * which divides into several separate 



* In making this statement I am not ignorant of Wright and Studer's figure of a transverse section of S. Tcollikeri 

 in the ' Challenger' Reports, to), xxxii. Alcyonaria, Suppl. pi. 6. fig. 5. Unfortunately I cut my sections and came 

 to the above conclusions after having inspected the British Museum material, so that I was not able to examine it 

 with this question of the branching of the canal-system in view. But when looking at the figure of the whole 

 colony on pi. i. of the same work, and seeing how extremely short, in fact almost non-existent, is the stem, it seems 

 probable that the section was taken at the base of a branch below the polyp-bearing portion but above the region 

 of " stem proper " after the main canal has begun to divide. Even if sections through other Siphonogorgids should 

 disprove the invariable occurrence of one central canal in the stem, the stiff smooth cylindrical stem and branches 

 caused by the ccencnchyme being completely packed with spicules must, I feel sure, remain as a specific diagnostic 

 character. 



