CLASSIFICATION OF ACTINIARIA 301 



tentacles are arranged so that more than one communicates with some 

 at least of the endocoels, and sometimes more than one with exocoels 

 also ; they may be simple, knobbed, or branched, and so on, and there 

 may be more than one sort in the same species ; they may be reduced 

 and wart-like (Part II, Text-fig. 3), or even reduced to nothing externally 

 visible. There are typically no siphonoglyphes — these are recorded in 

 some cases but their existence probably needs confirming. The mesen- 

 terial filaments have no ciliated tracts. Sphincters are absent or weak 

 diffuse. Sting-cells of a size characteristic more of Madreporaria than of 

 Actiniaria are usually present somewhere in the body (see Part II, 

 Text-fig. 6). There are usually a good many perfect mesenteries, as 

 a rule twelve or more pairs, and there is no distinction of them into 

 macro- and microcnemes. The longitudinal mesenterial musculature 

 consists typically of a feeble layer, not forming the sort of sheet or 

 retractor characteristic of Actiniaria (see Part II, Text-figs. 4 and 5). 

 Basilar muscles are absent. Ectodermal muscle present at least some- 

 times in the body-wall, sometimes probably absent. Directives usually 

 present, varying in number. The large sting-cells may occur in tentacles, 

 actinopharynx, mesenteries, body-wall. 



Family 1. Corallimorphidae. 



Corallimorphidae, Hertw., 1S8'2, \). 21 ; Carlgr., 1900, p. 19. 



Size larger or smaller ; habit solitary or gregarious, individuals may 

 be connected by coenosarc. Ectodermal muscle in body-wall present at 

 least in some cases. Tentacles simple, knobbed at the tips. Not more 

 than one tentacle per exocoel, more than one on at least the older 

 endocoels. 



Genera : C o r a 1 1 i m o r p h u s , I s o c o r a 1 1 i o ii , 

 Corynactis. 



Corallimorphtjs, Moseley, 1877, p. 299. 



Corallimorphidae with weak musculature throughout. Body-wall 

 ectoderm has weak longitudinal musculature. No sphincter. Body-wall 

 and oral disc may be very thick and cartilaginous, and animal may 

 attain fairly large size. Tentacles simple, and all knobbed at the tip 

 (see Part II, Text-fig. 14, g), divided into two sorts, marginal and 

 discal. There is never more than one tentacle of each sort arising 

 from one and the same endocoel. The exocoelic tentacles are the 

 smallest of the marginal series, taken on the whole, and the discal 

 tentacles correspond to the endocoels of the inner marginal tentacles. 

 There may be a good deal of irregularity. 



