CLASSIFICATION OF ACTINTARIA 297 



not very -strong, sessile circumscribed. Numerous perfect mesenteries. 

 Older mesenteries fertile, but probably not the directives. 

 Species : 

 A. dendrophora, H. and S., 1893, p. 123; Haddon, 1898, 

 p. 487. 

 And probably also A. villosa, Q. and G., 1833, p. 156. 



Family 14. Stoichactidae. 



Stoichactidae, Carlgr., 1900, p. 72 ; 1900 ( ' Ofv. Vet.-Akad. 

 ■Porh.'), p. 278. 



Discosomidae, Klunz., as used by Haddon, 1898, p. 469, 

 pro parte. 



Endomyaria with definite base. Column usually but not always 

 verrucose above. Size souietimes very large. Tentacles simple, but for 

 scattered bifid or multifid tentacles which sometimes occur sporadically 

 among the others ; they may be fairly long and quite ordinary, or may 

 be short or wart-like, or even short columns with spherical heads. They 

 are all of one sort in the same animal, and there is not more than one 

 to each exocoel ; the endocoels may in rare cases have only one tentacle 

 each, but usually at least some of them have more — the stronger ones 

 may have radial rows (see Part II, Text-fig. 14, f), or all the endocoels 

 may have either one or several rows. Sphincter strong or not very 

 strong, more or less diffuse to more or less circumscribed. Mesenterial 

 musculature well developed, retractors weaker or stronger but not 

 unusually strong, diffuse. Numerous perfect mesenteries. Gonads may 

 occur on all mesenteries^usually the older ones are fertile save some- 

 times the directives, but not always. Tentacular longitudinal muscle 

 ectodermal. 



Genera : Stoichactis, Eadianthus, Antheopsis. 



This family is itself very clearly marked off from others, 

 but within it, it is difficult to satisfactorily separate off genera. 

 The thfficulty is increased because some descriptions of the 

 forms do not give enough data. At best, it seems that there are 

 only three sound genera to be distinguished, three stages 

 in the evolution of very similar creatures ; they form a series 

 really, and I do not feel perfectly confident that they do not 

 all form one large genus. At any rate more than three it is 

 unwise to insist on ; some pairs of names have been given 

 to similar forms, and some of these must now become synonyms. 



y 2 



