ECOLOGY AND TAXONOMY OF Hdlimeda 



133 



Fig. 39. H. gigas. Holotype, Marshall Islands, Enewetak Atoll, Taylor 46-419. Actual 

 width of specnnen is 14-3 cm. (Photograph courtesy of the Division of Biological 

 Sciences, University of Michigan.) 



Nodal medullary filaments fusing completely in twos and threes, although 

 occasionally and most particularly towards the periphery of the node uniting 

 for only a short distance (incomplete fusion) ; fused groups entangled but at 

 most adhering only slightly. 



Type specimen. Marshall Islands, Enewetak Atoll, Taylor 

 46-419, 6 June, 1946 (MICH). 



Habitat. Pendant on rocks in relatively quiet water, and growing 

 from approximately — l-5m to —46 m. In shallow water it is 

 sometimes relatively common and at some sites it is associated with 

 H. macrophysa. 



Geographic distribution. North-western Pacific Ocean. 



This species may initially be mistaken for a large segmented tuna 

 or discoidea. Microscopic differences with tuna include the large surface 

 diameters of the peripheral utricles, these averaging 115 [xm in gigas as 

 compared to 70 [j,m in tuna and a less extensive development of the 

 cortex in gigas as opposed to tuna. 



