No. I.] ACTINIARIA OF THE BAHAMAS. 9 
specimen there was apparently a total absence of “ yellow-cells ” 
in the endodermal epithelium, while in others they were abun- 
dantly present. 
The tentacles are decidedly entacmzeous and very long, the 
inner ones measuring 3.4 cm. in length. In all the specimens 
examined they were arranged octamerously in five cycles, the 
formula being 8, 8, 16, 32, 64. Lesueur states that the “centre 
tentacula are about 6 or 8 in number,” and gives their length as 
somewhat greater than those I measured; z.¢., two or three inches. 
Whether the words quoted mean that the numbers given were 
simply approximate, or that in some forms the arrangement of 
the tentacles was hexamerous and in others octamerous, it is 
impossible to say; in no case have I observed the hexamerous 
arrangement. One of the most striking peculiarities of the 
species is the occurrence upon the tentacles of a number of 
elevated bands, one above the other, each extending only partly 
round the tentacle, the successive bands being connivent. They 
are usually of a different color from the rest of the tentacle, and 
in preserved specimens stand out very prominently. In trans- 
verse sections they are seen to be due to thickening of the 
ectoderm, the mesogloea not participating in their formation. 
In the thickening are numbers of nematocysts, while elsewhere 
these are few in number and apparently smaller, or else absent. 
The ectodermal muscular layer of the tentacles is not markedly 
developed, presenting no foldings in fully extended tentacles, 
and no traces of muscle cells enclosed in the mesogloea. On 
account of the absence of a circular muscle the tentacles are 
not infolded during contraction. 
The septa of the forms examined were in four cycles, the 
formula being 8, 8, 16, 32, and only those of the first cycle were 
perfect. A large mesenterial stoma is plainly visible on a level 
with the cinclides,—the outer one,— while the inner one is 
considerably smaller, but still quite evident. The Hertwigs 
(79) state that in A. dzaphana the inner stoma is the only one 
present, a statement which needs revision. There can be no 
question as to the existence of both the inner and the outer 
stoma in A. annulata, the size of the latter rendering all doubts 
as to its existence impossible. 
The longitudinal muscle bands are well developed, and in the 
primary mesenteries (Pl. III, Fig. 1) occupy about 4 of the 
