112 



L. HILLIS-COLINVAUX 



Geographic distribution. Pantropical; western and eastern Indian 

 Ocean including Red Sea; western Pacific both north and south; 

 north-eastern Pacific; western Atlantic, both north and south. 

 Not in Bermuda. 



Special features of the thallus of this species include segments with 

 a wide range of shapes, the occasional termination of a branch with 

 rhizoidal rope-like strands rather than segments, a feature also of a 

 few other species particularly micronesica, and the development in 

 certain specimens of two fairly dissimilar growth systems, an upright 

 (cushion) pattern and a spreading (axial) pattern. Of these, the spreading 

 system, which is somewhat loosely organized and composed of cylindrical 

 and deeply trilobed segments or occasionally subcuneate ones, often 

 produces discrete clumps of intense erect growth at intervals, in which 

 flat, relatively broad segments with entire slightly lobed margins are 

 often the most common. 



Halimeda goreauii W. R. Taylor 



Figure 29. 



Fig. 29. H. goreauii. Isotype specimen, Jamaica, St Ann Parish, reef off Cardiff Hall 

 beach at about — 30 m, T. F. Goreau et al. 3337. Scale bar is 2 cm. (PhotograiDh by 

 The Ohio State University Department of Photography.) 



