CLASSIFICATION OF ACTINIARIA 293 



not known whether Leiotealia has more than one tentacle 

 to each main endocoel and exocoel or not ; Hertwig apparently 

 thought only one, but the specimen is small and so contracted 

 (and Aureliania has cycles as well as radical rows) that 

 it is hard to tell. The other things seem to point to its being 

 an Aureliania, which in that case should be called 

 A. nymphaea, Hertw. ; whether it is A. nymphaea. 

 Drayt., is another matter. It has smootli body without 

 verrucae or acrorhagi, small button-like tentacles, pinnate 

 sphincter with stout mesogloeal axis, mesogloeal radial disc- 

 muscle ; only the mesenteries of cycles 1-3 have distinct 

 retractors, and these are great circumscribed things attached 

 only at one edge. These things are all found in Aureliania 

 (not necessarily only three cycles of mesenteries with retractors 

 of course), as are also the wide base and jDyramidal form of 

 nymphaea, and some of them are very characteristic 

 features. The sphincter is less developed in nymphaea 

 than in the others. In view of the general evidence it seems 

 prolmble that the Stichodactyline tentacle-plan may be 

 assumed. 



AcTiNOPORus, Duch,, 1850. (See Duerden, 1900, p. 174; 

 Carlgren, 1900, short paper on Htichodactylines, p. 283.) 



Aurelianidae with definite but not specially wide base — it may even 

 be somewhat reduced. Tlie body maj' be long. There may be rather 

 vesicle-like verrucae below the sphincter, of which the main ones some- 

 times form a sort of collar. Deep fosse. Disc not extensive, but notched 

 into little permanent lobes or lappets at its margin, which correspond 

 in number to the eudocoels and exocoels. Tentacles short vesicular 

 knobs, may be lobed, many communicating with each exocoel and 

 endocoel, the tentaculate areas thus formed separated from each other 

 by radial grooves. Sphincter strong circumscribed (see Part II, Text- 

 fig. 13, a). Mesenteries all perfect and all or mostly fertile, with very 

 strong circumscribed retractors which may be broadly or narrowly 

 attached to the mesenteries, partly according to region. Disc and 

 tentacle muscle very weak, ectodermal if present. 



Species : 



A. elegans, Duch., 1850, p. 10. (See Duerden, 1900. p. 175.) 

 A. elongatus, Carlgr., 1900 (small paper on Stichodactylines), 

 p. 283. 



