THE ANTHOZOA 57 



GRADE I.—PARAMERA. 



The primitive bilateral symmetry of the zooid is retained, or at most 

 is partially obscured by the secondary development of mesenteries in a 

 limited number of the primary intermesenterial chambers. 



Order 1. Cerianthidea. 



Solitary Zoantharia paramera without a skeleton. The mesenteries 

 are numerous, arranged symmetrically in pairs, each member of a pair on 

 opposite sides of the stomodaeum. The mesenteries devoid of muscle 

 banners. A sulculus present but no sulcus. Musculature chiefly in the 

 form of longitudinal ectodermal muscles supported by processes of the 

 mesogloea of the column. 



Family Ceriaxthidae. Genera — Cerianthus, Dell. Chiaje ; Bathy- 

 anthus, Andres ; Saccanthus, M. Edw. 



Order 2. Antipathidea. 



Colonial Zoantharia paramera with a spinose, horny, usually branch- 

 ing axial skeleton on which the zooids are seated. Six tentacles, of which 

 two corresponding to the ends of the long axis of the stomodaeum are 

 usually larger than the others. Six primary mesenteries always present ; 

 in most forms four others are developed, one in each sulco-lateral and 

 sulculo-lateral chamber, making ten. The two mesenteries at right angles 

 to the long axis of the stomodaeum are greatly developed, and alone bear 

 gonads. Muscle banners absent. 



Family 1. Antipathidae. The individual zooids have six simple 

 non-retractile tentacles, which may be radiately arranged or in two rows 

 of three each. Axis spinose and with a central canal. Ten mesenteries 

 are present. Sub-Family — Cirrhipathinae. The zooids are radiately 

 arranged on all sides of the axis. Genus — Cirrhijxithes, Blainville. Sdb- 

 Family — Antipathinae. The zooids are borne in linear series on one 

 side of the axis. The transverse axis of the zooid tends to be elongated 

 in the direction of the long axis of the stem and branches. Genera — 

 Antipathes, Pallas ; Stichojxdlies, Brook ; Antipathella, Brook ; Aphanipathes, 

 Brook ; Tijlopatlies, Brook ; Pteropathes, Brook ; Par antipathes, Brook. 

 Sub-Family — Schizopathinae. Zooids much elongated in the trans- 

 verse axis. On either side the two chambers adjacent to the reproductive 

 mesenteries are separated by a partition from the rest of the zooid, which 

 thus appears to be divided into three parts — two reproductive and one 

 gastral. Each division bears two tentacles. Genera — Schv:o2}athes, Brook ; 

 Bathypathes, Brook ; Taxipatlics, Brook ; Cladopathes, Brook. The last- 

 named genus has only six mesenteries. 



Noti:. — The Schizopathinae have been described by Brook as dimorphic, 

 but there is no division of labour accompanied by structural differentia- 

 tion amongst the zooids, and therefore there is no dimorphism. The 

 zooids are all alike ; each zooid is greatly modified in connection with the 

 greatly developed gonadial mesenteries, but there is no division into 



