126 ZOOPHYTES. 



moreover, that the smooth exterior sometimes graduates into the 

 pustulate ; moreover, the number of tentacles and of the series of 

 tentacles, is less in young individuals. 



The genus Discosoma of Leuckart, which comprised the depressed 

 species with rudimentary or obsolete tentacles, is not retained, inas- 

 much as the length of the tentacles, considered as a generic character, 

 is of slight importance. The flat disk shape belongs also to some 

 species with prominent tentacles. The genus Actinoloba of Blain- 

 ville is distinguished by an undulated or sublobate margin, a cha- 

 racter which fades insensibly, as we trace it through the different 

 species of Actinia. 



Ehrenberg's Cribrinae do not appear entitled to constitute a distinct 

 genus ; the lateral perforations which characterize them occurring 

 in naked as well as tuberculate species. This author also subdivides 

 the genus Actinia into the sub-genera, Isacmcea, those with equal ten- 

 tacles ; Entacmaa, those with the inner tentacles longest ; Ectacmcea, 

 those with the outer tentacles longest ; and Mesacmcea, those with the 

 medial longest. 



The genus Adamsia has been instituted by E. Forbes, Esq., for 

 the Actinia maculata of Adams, and is characterized as follows : body, 

 when expanded, bilobate, adhering by a broad base ; tentacles subre- 

 tractile, simple. 



I. TENTACULIS suiu:uns. 



1. Margine superno uniseriatim tuberculato. (Upper margin uniseriately tuberculate.) 

 a. Tentaculis disci dimidio fongioribus. ( Tentacles longer than Jialfthe disk.) 



1. ACTINIA FLAGELLIFERA (Dray ton). 



A. extus levis, medio 1|" crassa, infra supraque valde dilatata (2J" 

 lata), basi late lobata, margine superno uniseriatim tuberculata ; ten- 

 taculis longissimis (2-3") flagelliformibus, 3-seriatis ; ore prominulo, 

 elliptico. 



Exterior smooth; 1| inches broad at middle, upper and lower ex- 

 tremities much dilated (2J inches broad), margin of the summit 

 with a single series of rather large tubercles; tentacles very long 

 (2 to 3 inches), flagelliform, in 3 series; mouth somewhat promi- 

 nent, elliptical. 



