CLASSIFICATION OF ACTINIARIA 281 



It seems not unlikely that Phy lie discus is identical with 

 Triaotis, but it would be well to wait for the anatomy of 

 T . p r o d u c t a before assuming that and changing the name. 

 A species which might possibly come in here is the one described 

 by Hargitt as C r a d a c t i s variabilis. 



Family 6. Phyllactidae, sons, strict. 



Phyllactidae, Andres + Aliciidae, Duerden + Dendromeliidae, 

 McM., as used by Haddon, 1898, pp. 435, 433, 440, all pro 

 parte. Including Thaumactiniae, Fowler. 



Endomyaria with definite base. Body-wall variable ; it may be 

 wide and provided with vesicles below, narrower and naked above ; 

 oi" there may be vesicles all over it, with or without acrorhagi at the 

 margin ; or the lower part of the body may be devoid of vesicles, and 

 provided only with verrucae, while the vesicles are confined to the 

 sub-marginal zone, really representing foliose acrorhagi, and sometimes 

 forming a very definite collar or ruff ; or again, the sub-marginal region 

 may bear only about six vesicles or ' pseudotentacles ', which at their 

 best form large branching bush-like structures. In spite of this variation 

 vesicles are always present, and both they and any acrorhagi there may 

 be can be simple or compound. Tentacles simple, provided with sphincters 

 in one genus only ; so that usually they are non-deciduous ; their 

 longitudinal musculature ectodermal or mesogloeal. There may be 

 ectodermal longitudinal muscle in body-wall and actinopharynx. Mesen- 

 teries NOT divided into macro- and microcnemes, more than six pairs, 

 and usually twelve or more pairs perfect, with occasional exceptional 

 individuals. Sphincter absent, diffuse, or circumscribed. 



Genera : P h y 1 1 a c t i s , C r a d a c t i s , P h y m a c t i s , 

 Oystiactis, Bunodeopsis, Thaumactis, L e- 

 br unia. 



This family and its contained genera present a good deal of 

 difficulty. I have attempted a revision of them, but it may need 

 carrying a good deal further in the light of new knowledge. 

 A number of genera have been described under Phyllactidae, 

 Aliciidae, Bunodidae, Dendromeliidae, and Thaumactidae, 

 which need a good deal of sorting out. The principle upon 

 which one must work, of having two families (Aliciidae and 

 Phyllactidae) was introduced in Part II, p. 530, and the 



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