260 T. A. STEPHENSON 



IsACTiNERNUs, Carlgr., 1918, p. 29. 



Actinernirlae with distal part of body four-lobed, the lobes able to 

 bend in over the mouth. Wall with very little papillae forming nemato- 

 • t;yst batteries. Tentacles numerous, in at least two cycles, largest at the 

 apices of the disc-lobes, the inner with small aboral mesogloeal basal 

 swellings, the outer with the swellings slightei- or absent. Radial 

 musculature of disc and tentacles chiefly ectodermal. Actinopharynx 

 with very thick mesogloea. Mesenteries numerous, almost regularly 

 arranged, cyclic, the partners equal, many of them perfect. Weak 

 retractors in lower parts of older mesenteries. 



Species : 



I. quadrilobatus, Carlgr.. 1918. p. 29. 



Synhalcurias, Carlgr.. 1914, p. 68. 



II y ant hops is as used by Wassilieff, 190S, pro ))artp. 



Aetinernidae with the body not lobed above. There are little nemato- 

 cyst batteries in the column ectoderm. Tentacles without basal swellings, 

 up to over 100. Radial musole of disc tending to become mesogloeal, 

 longitu(Unal muscle of tentacles ectodermal. Numerous mesenteries, 

 all perfect in old specimens, their arrangement cyclic but not very 

 regular, the two partners of a pair generally aboxit equal. Mesenterial 

 musculature weak, not forming projecting retractors. 



Species: 

 S . e 1 e g a n s . Wass., 1908. p. 8. (See Carlgr., 1914, p. 68 ; and 1918, 



p. 27.) 



Sub-tribe 3. Mesomyaria, inihi. 



Nynantheae usually with a definite base and basilar inuscles, but 

 sometimes with a physa or an intermediate gi-ade of base ; sometimes 

 the base is reduced ; or it may be hollowed out into a cup or elongated 

 as a slit, &c. The form is variable, from a worm-like burrowing condition 

 to a broad flat dish shape or a flattened wiap-like condition, but the 

 typical anemone form (more or less cylindi'ical or vase shaped) is the 

 usual thing. In the advanced forms there is often a thick body-wall, 

 and some of these exhibit ornamental knobs or roughnesses, crests, and 

 so on. and in this connexion the tentacles may have aboral basal sweUings 

 of mesogloea. In some forms the body is divided into scapus and 

 eapitulum, and the scapus may have cuticle on it. There are never any 

 true vesicles or acrorhagi. but sometimes suckers or verrucae. CincUdes 

 often occur. The tentacles are usually simple, but may have the above- 

 mentioned swellings, or even, rarely, thickenings of other different 

 kinds. Their longitudinal musculature is ectodermal to mesogloeal. 



