CLASSIFICATION OF ACTINIARIA 309 



paper I mentioned (p. 487) this genns without being very- 

 definite about it. I do not think a final decision can be made 

 even now, but if these cincHdal non-acontiated forms are 

 estabhshed they will probably need a family Stephanaugidae, 

 one of the further combinations foreshadowed in Part I. From 

 the fewness of their cinclides, and from their general characters 

 one imagines the cinclides to be vestiges not to last much 

 longer, and probably the forms are descendants of Metridiid 

 ancestors which have lost the acontia before all the cinclides ; 

 but it is not even certain yet that there are not really rudimen- 

 tary acontia, easily overlooked, present, in which case the forms 

 are actually queer Metridiidae on the way to forming Chon- 

 dractiniid or Actinoscyphiid or other stages. S. tuber- 

 culata, at least, has basal mesogloeal swellings to some of 

 the tentacles. If the others have not they need separation, 

 and the whole genus and its relations need careful revision. 

 The related (?) Amphianthus seems to be an Actino- 

 scyphiid, so far as it is at present known. 



2. S y n a n t h u s , Verr. , is probably P a r a n t h u s . 



3. Ammophilactis, Verr., 1899, p. 213. 



Body may be long, with small base, divided into smooth scapus with 

 a collar in which is the mesogloeal sphincter, and capitulum with suckers 

 which can attach grains of sand. Tentacles in more than two cycles in 

 the adult. Numerous perfect mesenteries. Strong apparently diffuse 

 retractors. Older mesenteries fertile. 



A. rapiformis, Les., 1817, p. 171. (See Verrill, 1899, p. 213.) 



This seems clearly a Paractid, differing from Pseudo- 

 p a r a c t i s in its single sphincter and suckers. 



4. Archactis, Verr., seems very near or identical with 

 Antholoba. 



5. Raphactis, Verr., 1899, p. 144. 



Definite base, broadly expanded or stem-clasping. Column with 

 a capitulum which may be more or less ridged, and a scapus which is often 

 ridged at the top, where the mesogloeal sphincter Ues, and may also be 

 tuberculate. Twelve or more pairs of perfect (and at least mostly) fertile 

 mesenteries, others may be fertile too. Diffuse retractors. Tentacles in 

 more than two cycles in the adult. 



R. nitida, Verr., 1899, p. 144. 



R. caribaea, Verr., 1899, p. 205. 



