186 J. E. Durrpen—Jamaican Actiniaria : 
occurs also in the proximal region of many Actiniaria after the ciliated streak 
has ceased to exist. 
The mesogleeal axis of the mesentery, completely surrounded by a weak 
musculature, passes into the base of the filaments, and there becomes slightly 
expanded, sending a branch to each side. The cells on the anterior or inner 
border are much longer than on the sides and behind. ‘They are mostly 
strongly ciliated supporting cells, with which are mingled glandular cells of 
various kinds, and large oval nematocysts with a loose internal thread. The 
latter are of the same form as occur more rarely in the ectoderm of the stomodeeum 
and knobs of the tentacles. 
In the stomodeeal region the imperfect mesenteries are devoid of filaments ; they 
appear, however, immediately below and completely resemble those on the chief 
mesenteries. 
Proximally the mesenteries branch at their free termination, each branch 
being capped by a filament in which the large nematocysts predominate. 
No gonads were present in any of the polyps examined. 
On one occasion six specimens were collected at Drunkenman Cay, all closely 
associated within a crevice in the coral rock in shallow water; and another time 
several polyps were come upon living together on a live Pinna shell from Harbour 
Head, Kingston Harbour. When irritated they are capable of sending out 
quantities of clear mucus. 
The species was first obtained by Duchassaing and Michelotti from St. 'Thomas, 
and described by them under the term Draytoma myrcia; Andres places it among 
his ‘‘ Corynactidee dubiz,” under the genus Corynactis. The correctness of this 
generic transference I have already referred to. 
Its histological characters should be compared with those of C. australis (1896, 
pp. 152-8), and it will be seen that the two closely agree. ‘The mesenteries 
are, however, more regular, and the sphincter muscle slightly better developed in 
the present species. The sphincter also differs from that of C. viridis, Allm. (1896, 
pl. vil., fig. 11), 
The connexion of one polyp with another by a basal expansion, and the usual 
occurrence in groups are indicative of asexual reproduction, a method already 
known to occur in the British Globehorn, C. viridis (1860, p. 291). The 
irregularities in the arrangement of the mesenteries noted in C. australis (1896, 
p. 152), and in C. hoplites (1898, p. 468), are probably also due to this process. 
In the Australian representative it was found that some specimens possessed only 
one pair of directives, while others had two. 
Attention should be directed to the tetrameral arrangement of the mesenteries, 
corresponding with the tetrameral tentacles; the extraordinary development of 
