THE ANTHOZOA 59 



Family 1. Gonactinidae. Sulcus and sulculus present. Eight 

 Edwardsian macromesenteries and eight micromesenteries. The sulcar 

 and sulcular macromesenteries are sterile, the four remaining macro- 

 mesenteries are fertile, and form couples with four micromesenteries. Of 

 the four remaining micromesenteries there is a couple in each sulculo-lateral 

 chamber. Genus — Gotiadinia, Sars ; Gonadinia prolifera reproduces itself 

 asexually by strobilisation. Family 2. Oractidae. No sulculus. 

 Mesenteries as in Gonactinia, with an additional couple of micromesenteries 

 in the transverse chambers. Genus — Orudis, M'Murrich. Family 3. 

 MoNAULiDAE. Sulculus absent. Fourteen tentacles and fourteen complete 

 mesenteries arranged as in Gonactinia, but the sulculo-laterals are absent. 

 Genus — Scyto^ihorus, Hertwig. 



GRADE II.—CRYPTOPARAMEBA. 



Zoantharia in which the primary bilateral symmetry is obscured by 

 radial development of the second and succeeding cycles of mesenteries. 



Order G. Actiniidea. 



Colonial or solitary Zoantharia cryptoparamera, witli or without a 

 skeleton. Sulcus and sulculus both present (with rare exceptions). 

 Mesenteries arranged in cycles. Each cycle consisting usually of twelve 

 couples of equal size. Typically a couple of new mesenteries is formed 

 in each exocoele formed by previously existing cycles. The muscle 

 banners of the sulcar and sulcular directive mesenteries are turned away 

 from one another ; in all other couples they are vis d vis. Tentacles equal 

 in number to the mesenteries, one over each endocoele and exocoele. 



Sub-Order 1. Malacactiniae. Solitary Actiniidea or A'ery rarely 

 formin" colonies. Without a skeleton. 



Group A. Hexactiniae. 



Family 1. Ilyanthidae. Free Malacactiniae, not adhering by a basal 

 disc. Aboral end of body rounded. Sub -Family — Halcampinae. 

 Tentacles twelve. Mesenteries twenty-four — six couples complete, six 

 couples incomplete. Genus — Halcampa, Gosse. Sub-Family — Ilyan- 

 THiNAE. Genus — Ilycnithus, Forbes. Sub- Family — Peachiinae. Ten- 

 tacles twelve. Mesenteries twenty ; six primary couples complete, fertile ; 

 four secondary couples, the sulculo-lateral couples being absent. A single 

 conchula present. Genus — I'eachia, Gosse. 



Family 2. Actixidae. Malacactiniae with an adlierent ba?al disc. 

 Tentacles simple, uniform, arranged in cycles on periphery of peristome, 

 one tentacle over each exocoele and endocoele. Sub-Famii.y — Antheinae. 

 ^larginal tubercles present. No circular muscle. No acontia. Genera — 

 Adinia, Browne ; Anemonia, Risso ; Comadis, M. Edw. Sub-Fajiily — 

 Sagartinae. Circular muscle present. Acontia present. Primary 

 mesenteries alone complete, and are sterile. Division A. Circular muscle 

 endodermal. Genus — AdinoIoha,VAa.m\-[\\e. Division B. Circular muscle 



