Boone, Coelenterata, Cruises of "Ara" and "Alva" 33 



COELENTERATA 



Order: HYDROIDA 

 Family: CLAVIDAE 



Genus: CORYDENDRIUM Van Beneden 

 Corydendrium splendidum, new species 



•f 



Plate 4 



Type: A large colony taken in one fathom, at low tide, in 

 Kaneohe Bay, Oahu, Hawaiian Islands, December 15, 1928. 



Distribution : Littoral zone of Hawaii. 



Technical description : Trophosome : Colony with a strong 

 creeping, much branched, netlike hydrorhiza which gives rise to 

 a much branched hydrocaulus, fascicled at the base, attaining a 

 height of five to six inches, the primary ramification irregular, 

 but with the successive branches uniformly alternate and disti- 

 chous in their division, giving rise throughout their length, on 

 the exposed upper or distal sides, to short branches which support 

 the hydranths on their tips. The perisarc is horn-like, firm, elas- 

 tic ; the primary stem annulated with two or three rings at each 

 joint and the branches with six to eight rings at the origin of 

 these and the yet smaller branches which are the hydrophore-like 

 supports of the hydranths. These hydrophore-like branches may 

 be distributed alternately to the left and right of the supporting 

 branch, or irregularly if the latter arrangement achieves a more 

 advantageous distribution. The hydrotheca have an elongated, 

 narrowed, ovoidal body, with numerous short to medium length 

 filiform tentacles irregularly distributed over the surface, these 

 tentacles varying in the hydranths examined from four to six 

 short, button-like protuberances encircling the distal end to six- 

 teen to twenty tentacles of medium length irregularly distributed 

 over the entire body ; in those where the greatest tentacle develop- 

 ment exists some of these tentacles form a simple, encupping 

 circle around the base of the hydranth body and vary in length 

 from one-third to one-half the length of the body ; while above 

 these, on the same body, shorter tentacles occur, in some instances 

 nearly concealing the body, giving it a black-berry-like appear- 



