CLASSIFICATION OF ACTINIARIA 249 



Oractis, McM., 1893, p. 138. 



Gonactiniiclae (?) in which only the eight protocnemes are fertile and 

 filamented. There is no definite base, and there are only ten tentacles. 

 Species : 



O. diomedeae, McM., 1893, p. 1.38. 



This genus is not yet very fully known, but is probably 

 referable to this family. 



Tribe 2. PTYCHODACTEAE,mihi. 



Containing the family Ptychodactidae only. 



Actiniaria with a definite base, which may rather merge into the 

 column, but without basilar muscles. Body-wall smooth or with 

 vertical rows of hollow outgrowths ; in structure, however, similar to 

 the tentacles, with ectodermal muscle-sheet and at least usually spiro- 

 cysts. Sphincter absent or weak difl^use endodermal. Tentacles few 

 or more numerous, simple. Actinopharynx either quite rudimentary 

 and reduced to a narrow band, or else quite well developed and provided 

 with siphonoglyphes and ectodermal muscle-fibres. Six to twelve or 

 more pairs of mesenteries perfect. Musculature of mesenteries weak, 

 hardly forming retractors. The free borders of the mesenteries (or their 

 representatives if the mesenteries fuse below) are occupied by filament 

 above and gonad below, not both together. The filaments have no 

 ciliated tracts, but those of the imperfect mesenteries end up above in 

 a curious structure like a bisected funnel, unusual in form and make-uj). 



Family 1. Ptychodactidae, Appellof, 1S93. 



See also Carlgren. 1911, p. 12, &c. 



With the characters of the tribe Ptychodacteae. 



Genera : P t y c h o d a c t i s , D a c t y 1 a n t h u b 



Ptychodactis, Appellof. 1893. p. 4. 



Ptychodactidae with about 100 tentacles or more. Smooth body. 

 No sphincter. Actinopharynx rudimentary, reduced to a nairow band 

 just inside the lip, which is produced at certain jjoints into lappets for 

 the attachment of larger mesenteries. Mesenteries irregularl 3- arranged ; 

 primaries and usually secondaries perfect. 

 Species : 



P. patula, Appellof, 181)3, p. 4. (See also Carlgren, 1911.) 



T 2 



