ECOLOGY AND TAXONOMY OF Holimeda 113 



Halimeda goreauii Taylor (1962), p. 173, Figs 1-7. 



Holimeda opuntia f. minor Vickers (1905), p. 57; Taylor (1928), p. 83, 

 Plate 10. 



Plants at least to 13 cm tall from a small stupose base, simple below, a 

 few of the lower segments subterete, above abundantly loosely branched, 

 with branches lying essentially in a plane ; segments at the bases of the lower 

 branches subterete to subcuneate, those above and in all the upper branch- 

 ing deltoid to most characteristically strongly trilobed, the lobes terete 

 in the central parts of the plant, more flattened above, the segment faces 

 shiny, often slightly ribbed, the margins minutely erose, in length 2-5^-0 mm, 

 in width 2-5-5-0 mm, the upper segments generally wider in proportion than 

 the lower ones. 



Cortex generally of three or more series of utricles, not utriculiform ; 

 peripheral utricles remaining attached for a distance of up to 5 [jim, appearing 

 somewhat rounded or hexagonal in surface view, (12-)16-37 [i,m in surface 

 diameter, (12-)17-40 [xm long in section; secondary utricles 10-30 [xm broad. 



Nodal medullary filaments uniting in pairs for a distance of approximately 

 1-5 times the filament diameter, at times adhering strongly with other pairs. 



A separate form has been described. 



f. compacta W. R. Taylor 



Halimeda goreauii f. compacta Taylor (1962), p. 174. 



Plants to 4 cm tall, short stalked and very densely branched, the upper 

 segments a little smaller and less sharply trilobed than in typical plants. 



Type specimens. For H. goreauii f. goreauii Jamaica, St Ann 

 Parish, reef off Cardiff Hall beach at about — 30 m, T. F. Goreau 

 et al. 3337, 21 July, 1961; for f. compacta Jamaica, St Ann Parish, 

 Llandovery, on the reef sill at — 33m to — 57m,T.F. Goreau A3 3 62, 

 31 December, 1960. Both in Museum of Science, Institute of 

 Jamaica (isotypes MICH). 



Habitat. Growing attached to rocks from near low-tide line to 

 — 65 m or more, in places associated with H. opuntia. 



Geographic distribution. Western Atlantic. 



Halimeda minima (W. R. Taylor) Colin vaux 



Figure 30. 



Halimeda minima (W. R. Taylor) Colinvaux (1968a), p. 32, Figs 5, 6. 

 Halimeda opuntia f. minima Taylor (1950), p. 82, Plate 39, Fig. 2. 



