REPORT ON THE ACTINIARIA. 41 



ou the foundation, is completely free from incrustation. The soft mesoglcea of the 

 ccenenchyme is, with reference to histological differentiation, in the same relation to the 

 body-wall as it is in Zoanthus, since here also, in addition to the other points of marked 

 agreement, the nucleated fibres are supplanted by mesogloeal cells. 



" With a view to observing the mesenterial arrangement, I studied two examples, 

 one of medium size, and one fully grown ; both exhibit the regular macrotype. In the 

 •younger specimen occurred a symmetrical arrangement of the pairs of mesenteries ; 

 of these there were sixteen, seven being regularly distributed on each side of the 

 ■directives. The other polyp possessed nineteen pairs, of which nine were situated on 

 the one side, and eight on the other." 



Epizoanihus elongatus* n. sp. (PI. I. fig. 2). 



" The individual polyps form elongated cylindrical tubes, the body-wall is flattened 

 'above, with a marked indentation, but terminates without radial furrows ; colour of 

 the colony a yellowish-grey." 



Habitat. — Station 322, off Monte Video; February 26, 1876 ; 21 fathoms. 



Dimensions. — Height of the polyps, - 05-l'0 cm. ; breadth, - 15-0 '4 cm. 



" This species can only be externally distinguished from the preceding. The 

 colony is 10 cm. high, consisting of about 100 individuals, and lives on a bundle of 

 the siliceous threads of a Hyalonema, about 3 mm. only in thickness. The largest 

 polyps are long cylindrical tubes, about 8-10 mm. high and 3-4 mm. broad ; in their 

 neighbourhood occur gradations to the youngest buds, which are small warts projecting 

 from the ccenenchyme, of 0"5-2 mm. in height, l"5-2"5 mm. in breadth. All the 

 animals are in a state of the most marked contraction ; the horizontal upper surface of 

 the body-wall is more or less flattened, and exhibits a circular indentation. This part 

 of the body-wall is entirely free from radial ridges and furrows. The colour of the 

 colony is a greyish-yellow. 



" The body-wall is thinner than in the preceding species, and possesses in its 

 outer zone the same deposits, though in smaller quantity. The remaining anatomical 

 and histological relations agree closely with those of the former species, but it is 

 important to observe that the sphincter is less strongly developed. The body-wall is 

 drawn inwards less deeply ; its sphincter is in transverse section correspondingly short, 

 but curved, and pointed at both ends. The generative organs consisted of ova in the 

 five specimens investigated." 



Epizoanthus cancrisocius* Studer (PI. I. fig. 15). 



Colony much incrusted, and consequently so brittle as to break readily in pieces ; 

 individual polyps slim, body-wall at the upper end bent outwards in the contracted 



(ZOOL. CHALL. EXP.— PART LXX1II.— 1888.) Dddd 6 



