530 T. A. STEPHENSON 
grade of sphincter ; and that, it is evident, is bound to vary 
within the limits of some families. 
A series of sphincters is illustrated in Text-figs. 11 and 12, 
all of them being taken from Actinidae in the new sense. 
A more evenly graded set could, I think, be made, but I have 
not material for it. But this one brings out the facts that 
I have wished to emphasize fairly well. 
§K. The Forms with Vesicles. 
The anemones provided with vesicles should (see p. 500) 
be kept apart from those without them, but among themselves 
there are two kinds at least. 
Taking the vesicled genera together, one can list nine 
clearly-distinguished ones-—Alicia, Phyllodiseus, Thau- 
mactis, Bunodeopsis, Phyllactis, Phymactis, 
Cradactis, Cystiactis, and Lebrunia. 
There have been families in existence to cover these forms 
(Aliciidae, Phyllactidae, Dendromelidae, Thaumactidae), but 
the definitions have been based chiefly on the form and situa- 
tion of the vesicles, and this seems as unnatural as it used 
to be to separate Hormathia, Chitonactis, Chito- 
nanthus, and Chondractinia on account of variation 
in ridges and tubercles ; and it has not been a very intelligible 
arrangement. So long as the vesicles are present, that is 
the family-character; their form and situation are more 
questions of generic distinction. Irom this point of view the 
families fall to the ground. ‘’he Dendromeliidae lapses in any 
case ; it was formed to cover Lebrunia andOphiodiscus. 
Ophiodiscus seems to be a typical Paractid (sce Part I, 
p. 560), and in the present state of our knowledge it seems very 
doubtful whether, although it is a distinct enough genus, there 
is anything to keep Lebrunia out of the Phyllactidae. 
The genus Thaumactis does not seem worthy, as we know 
it, to have a family to itself either. The other two families 
(Aliciidae and Phyllactidae) must be retained, but revised in 
the light of mesenterial arrangement, &c. 
(a) Alicia and Phyllodisecus are delicate creatures 
with vesicled scapus and naked capitulum, or with the vesicles 
