Actinaria G 93 



Sub-family CHONDRACTININ^ Haddon. 



Chondractinince HADDON, Sci. Trans. Royal. Dublin Soc., vol. IV, part V, 

 pp. 304, 305, 1889, (Revision British Actiniae, Part I). McMuRBicn, 

 Proc. U. S. Nat. Museum, vol. XVI, p. 183, 1895. 



Lower part or most of the column is usually more or less firm and often 

 verrucose; upper part is differentiated. It is softer or more flexible, often 

 with crests or flutings, or defined by a transverse row of verrucse, and is capable 

 of being strongly infolded; outside of the lower part of the column may have a 

 more or less adherent epidermal coating; cinclidse few, not to be easily detected 

 unless in use while living. Acontise are present but not numerous. Tentacles 

 contractile, large, numerous, in several hexamerous cycles. Two siphonoglyphs 

 and two pairs of directive mesenteries are normally present. Usually there are 

 six or twelve pairs of wide perfect mesenteries, which may be sterile, but many 

 other pairs may be attached to the upper part of the stomodgeum, near the oral 

 disk. Sphincter muscle is mesoglceal and usually strong. Base may enclose a 

 ball of mud for anchorage, or it may be attached to stones, etc., or it may clasp 

 and surround slender supports, such as the axes of alcyonarians. 



Actinauge Verrill. 



Actinauge VERRILL, Bull. Mus. Comp. Zool., Vol. XI, p. 50, 1883. Type A. 

 verrillii, formerly Urticina nodosa Verrill (non Miiller) . 



Actinauge HADDON, op. cit.,1, p. 317,1889. McMuRRicn, op. cit., p. 183, 1893. 



Large actinians of the subfamily Chondractininse, having the tentacles 

 and upper part of the body or capitulum capable of involution. Integument 

 of the body formed of two kinds; that of the lower part is firm and often thick, 

 with persistent, solid verrucse or tubercles, usually in vertical rows, and often 

 more or less covered with a thin, tough, epidermal coating; that of the upper 

 part of the body forms a marginal, brighter coloured capitulum below the ten- 

 tacles, where it is softer and lubricous, secreting mucous abundantly, and 

 usually rising into longitudinal ridges, crests, or oblong tubercles, which run 

 to and unite with the bases of all or nearly all of the tentacles. Cinclidse are 

 few, scattered, and inconspicuous among the verrucse, Acontia are present. 

 The basal disk may be broad and flat, adherent, or it may be bulbous, clasping 

 mud, or it may ensheath the branches of Gorgonidse, etc. Tentacles long and 

 large with a basal aboral lobe, contractile and retractile. The basal lobe may 

 be inconspicuous in strongly contracted specimens, or the distal part may be 

 partly invaginated into the basal lobe in some cases. Lips with large folds and 

 two gonidial grooves. 



The soft submarginal band or capitulum is usually phosphorescent, due 

 to the mucous. In contracted specimens it is usually entirely invected and 

 concealed. 



This genus, like Actinernus, has marginal elevations of the wall, running 

 to and uniting with the outer bases of the tentacles, but in Actinernus, 

 there is no specialized submarginal zone or capitulum, and the body is not 

 verrucose. 



The sphincter muscle is large and mesoglceal. Six or twelve pairs of 

 mesenteries are perfect and usually sterile in the middle part of the body, but 

 many more may be perfect near the disk; usually only the six large primary 

 pairs reach the base of the stomodseum. Mesenteries may form four to six 

 hexamerous cycles, or even more in large examples. Mesoglcea is very thick, 

 especially in the upper part of the column at the parapet. 



