Part II. — Stichodactylince and Zoanthere. 173 



cells stain more deeply, and, compared with the more apical region, fewer gland 

 cells are discernible. 



At various places around Port Antonio, on the north-east side of the island, 

 the species occurs in some abundance, usually with the column and part of the 

 disc buried in the sand or among the roots of various marine plants, such as 

 Thalassia and Ruppia. In water of from 4 to 5 feet around the bathing place 

 belonging to the Titchfield Hotel many specimens are to be found, including the 

 green variety. It does not affect a social habit, as is often the case with the 

 previous species, and is entirely absent from around the Port Royal Cays and other 

 spots on the south side of the island. 



Duchassaing and Michelotti met with the form at Guadaloupe and St. Thomas. 

 Ellis records it merely from the West Indies. 



Though there can be no doubt as to the distinctness of these two West Indian 

 Discosomids, yet, owing to the incomplete descriptions and figures of the earlier 

 authors, some difficulty exists as to their identification with one or the other of 

 Ellis's species. Assuming that the distinctions between the two forms indicated 

 by Ellis were simply due to different degrees of contraction, or to age, Professor 

 M'^Murrich regarded them as synonymous, and describes both as D. anemone. Not- 

 withstanding the few details given by the older writers, there is every likelihood 

 that M^Murrich's Bahaman representative is really the helianthus of ElUs, and 

 also of Duchassaing and Michelotti, and this is the determination which I have 

 followed above. Ellis mentions the flat salver-shape for helianthus, while 

 Duchassaing and Michelotti refer to the greenish-brown verrucae ; again, Ellis 

 records the angular form of disc of anemone, and the two later authors refer to 

 the colour variation. 



I follow Haddon (1898, p. 473) in transferring helianthus (= anemone, 

 M°Murrich} to his new genus Stoichactis, and find it necessary to erect another 

 genus for anemone. 



The following tabulated characters will enable the two to be readily dis- 

 tinguished in collecting : — 



Stoichactis helianthus. Homostichanthus anemone. 



Polyps often closely associated. Column short, Polyps scattered. Column long, cylindrical, 



salver-like, verrucose, usually not embedded ; little non-verrucose, usually completely buried ; capable 



retractile power. of considerable retraction. 



Disc flat ; an outermost cycle of tentacles alter- Disc sinuous ; a series of about twelve cycles of 



nates with all the other rows. Occasionally more tentacles constitutes a distinct peripheral zone. 



than two gonidial grooves. Only two gonidial grooves. 



Colour of tentacles mostly greenish yellow, Colour of tentacles bright emerald green, with 



with lighter and darker patches ; undergo no rapid opaque white and brown ; stronger colours readily 



variation in intensity. change in intensity. 



IKANS. EOr. DUB. SOC, N.8. VOL. VII., PABT VI. 2 C 



