ECOLOGY AND TAXONOMY OF Halimeda 19 



death of the Duke, but nonetheless he collected some 800 new plant and 

 animal species during the 15 months of his stay (Sloane, 1707). Among 

 these was the second species of Halimeda to be discovered. In his volume 

 dealing with the natural history of Jamaica, Sloane (1707) called this 

 species Corallina opuntia. It is what is now known as Halimeda opuntia, 

 the straggly cushion-shaped clusters of which are a prominent feature 

 of shallow parts of Caribbean reefs. Sloane's specimen is contained in 

 the Sloane Herbarium of the British Museum (Natural History). 



A. Ellis: microscopy and the plant or animal question 



The most significant contributor to early Halimeda history, how- 

 ever, was John Ellis, one of the outstanding naturalists of Great 

 Britain of the last half of the eighteenth century. Indulging his interest 

 in plants and animals of land and sea, he developed a network of 

 correspondents in various parts of the world, especially America and 

 the West Indies, receiving from them numerous materials for study. 

 His eventual appointments as King's Agent for the province of West 

 Florida (1764) and the Island of Dominica (1770) provided him with 

 sufficient income to follow his inclinations more freely (Smith, 1819; 

 Savage, 1948). 



Of especial interest to Ellis were the "Corallines", a group of cal- 

 careous and horny sea organisms which he successfully established as 

 an animal group in his classic "Essay Towards a Natural History of the 

 Corallines" of 1755, although Peyssonnel had somewhat earlier recog- 

 nized an animal nature in at least some of them (Savage, 1948). This 

 coralline group was diverse, and although the principal representatives 

 were various cnidarians, the complex also included calcareous sea 

 organisms such as the green alga Halimeda and the red alga Corallina. 

 Because of this, two Halimeda species, subsequently known as incrassata 

 and opuntia, were included in the 1755 publication as "Articulated 

 Corallines of Jamaica". 



Eventually Ellis separated five species of Halimeda: incrassata, 

 tridens, monile, opuntia and tuna, but the genus had not been established 

 as yet, and they were assigned to Corallina. As such they appear in his 

 treatise with Solander (Ellis and Solander, 1786), published after the 

 death of both Ellis and Solander under the direction of Ellis' daughter, 

 Martha Watts. The use of binomial nomenclature in this work and in 

 an earlier publication (Ellis, 1767) probably grew out of his extensive 

 correspondence with Linnaeus and work with Solander, a favourite 

 student of Linnaeus. Four of the species with their epithets are still 

 accepted; the remaining one, tridens, has been placed in synonymy 



