156 J. E. Duerden — Jamaican Actiniaria : 



My reasons for transferring this genus from the family Rhodactidee, where it 

 has usually been placed, to the family Discosoniidas, are given under the discussion 

 on the former family. 



Succinctly, the history of the genus is as follows : MM. Duchassaing and 

 Michelotti (1860) first established Ricordea for the species about to be noticed; 

 in 1877, Klunzinger erected the genus Heteranthus for a very similar form, 

 H. verniculatus, from the Red Sea ; Andres associated this latter species with the 

 genus Actinothrix, which Duchassaing and Michelotti had erected for the form 

 here described as Actinotryx Sancti-Thomce, placing Ricordea florida among the 

 "species incertse sedis." M c Murrich (1889), considering Duchassaing and Miche- 

 lotti's definition of their genus Ricordea to be only specific, not generic, in 

 character, disregarded it in favour of Klunzinger' s Heteranthus ; in a later paper 

 M°Murrich (1896) returns to the original term Ricordea. 



As at present known the genus includes with certainty only the one species, 

 R. florida. The precise position of Heteranthus verniculatus cannot be established 

 until an anatomical examination of it has been made. Haddon (1898, p. 481) 

 suggests that two or three other species, described under different generic terms, 

 may also be included along with R. florida. 



Ricordea is undoubtedly closely allied to the two genera Discosomoides and 

 Discosoma, as these are defined by Haddon (p. 470) from Simon's researches. 

 The three agree in having a smooth column-wall, tuberculiform or papilliform 

 tentacles, no gonidial grooves, numerous perfect mesenteries, and sphincter 

 muscle absent or weak. Both R. florida and D. nummiforme are, in addition, 

 characterized by the clearness of their mesoglcea, and the exceptional structure of 

 their mesenterial filaments. 



Ricordea florida. — (PI. x., fig. 7; PI. xi., figs. 5, 6; PL xir., figs. 1, 2 ; PI. xm., 



fig. 1 ), Duchassaing and Michelotti. 



Ricordea florida, . . Duchassaing and Michelotti, 1860, p. 42, pi. vi., 



fig. 11 ; 1866, p. 122 ; Andres, 1883, p. 572 ; 

 M c Murrich, 1896, p. 188. 



Heteranthus floridus, . M c Murrich, 1889, p. 47, pi. i., fig. 10 ; pi. iv., 



figs. 4—5. 



The base is usually smaller in diameter than the column, and adheres so closely 

 to the irregular surfaces of coral rock as to render almost impossible the removal 

 of the polyp without injury or the separation of fragments of the rock. 



The column is short and variously outlined. Simple forms are cylindrical, but 

 compound examples are elongated laterally and sinuous above ; the limbus is 

 generally irregular, and often of less diameter than the more distal part of the 



