REPORT ON THE ACTINIARIA. 43 



structure. 1 have been unable to detect generative organs in any specimen 

 investigated. 



" Owing to the abundant incrustation, the body-wall Ijeeomes as hard and brittle 

 as stone, and does not permit therefore of investigation by means of sections. In this 

 case therefore, and in the remaining forms with similarly strong incrustation, I made 

 use of the method of grinding tested and recommended by G. v. Koch in his researches 

 on Tuhipora. 



" The body-wall is of considerable thickness ; its mesogioea exhibits a structure very 

 different from the remaining species of Epizoanilius, as being penetrated by deposits 

 throughout its whole depth. These deposits consist of particles of sand with ij-regular 

 angles, and are set in a strong circular fence, reducing the mesoglcea to thin lamellae ; liut 

 there persists a very narrow internal lamella bounding the endoderm all round. In the- 

 homogeneous mesoglcea-lamellse are situated roundish cells which give oflF fine radiating 

 processes, and fine fibres provided with nuclei ; the presence of the ceU-heaps, which 

 are to be met with in the remaining species of EjyizoantJius, I was unable to 

 demonstrate in this case. A transverse section through the wall of the shell exhibits 

 a similar condition in the ccenenchyme. This latter is also of considerable thickness, 

 and is internally traversed l)y the large endodermal tubes which connect the various 

 coelentera tosfether. 



" The body-wall is, as has lieen already mentioned, 1)eut above at a sharp angle, 

 thus forming a plate-like surface. In contrast to the remaining members of tlie 

 genus, where it turns deeply inwards vertically, it is liere only sliglitly invaginated, a 

 diflference resulting from the slighter development of the sphincter. The latter com- 

 mences to a certain extent on the horizontal part of the body-wall, and thru thickens 

 gradually into a truncated muscular mass, which appears fusiform in section, and is 

 only slightly curved inwards. It lies enclosed in the innermost lamella of mesoglcea ; 

 the latter is thus much thickened, and is free from adventitious . deposits. The 

 sphincter is on both sides bounded by a layer of mesoglcea, which extends inwards to 

 the commencement of the oral disc, is charged with the usual accretions, and is a direct 

 continuation of the outer sandy layer." 



So much for the anatomical description given by Erdraauu, which sulficiently 

 proves that Epizoanthus canci-isocma must be separated sj'stematically from Epizoanihus 

 parasiticus, the latter possessing larger and coarser polyps and tar less incrustation. 1 

 have identified the animal with the Epi'Manthus catwrisocius of Studer, as lie records 

 for his specimens similar dimensions, and a marked incrustation, at least for the basal 

 membrane.' In other points his description is not sufficiently exhaustive, and this i,s 

 still more true of Gray's account." Only the statement of the latter that the large 



» Afimat.ibcr. tl. k: AhaJ. d. Wiss. Berlin, 1878, p. r.47. 

 = Proc. Zool. Sor. Loud. 18G7. p. 237. 



