REPORT ON THE ALCYONARIA. 255 



eight more or less distinct longirudiiuil furrows, which extend sometimes throughout 

 the entire length, sometimes only along the upper portion. The body-wall projects in 

 ridges between them. The mesoderm of the polyp is beset with spicules which are 

 (•losely apposed to one another and so make the calyx into a rigid tube. 



These spicules are for the most part thick spindles, covered all over with rough 

 warts, and enlarging at one end into a club-like form. Rod-shaped curved spicules also 

 occur, esjjecially in the longitudinal grooves. The retractile portion of the jiolyps 

 contains either no spicular elements, as in Clavularia crassa, or thin spindles and rods 

 which may extend even into the tentacles. They are usually disposed in eight 

 longitudinal strands, which are then continued into the tentacles. 



Even the oesophageal tube may contain spicules-, as for instance in Clavularia 

 frigida, Danielssen. In the colonies united by stolons, the stolons arise from the 

 bottom of the calj'ces, which become narrowed at their bases and give origin to one 

 or more cylindrical or flat processes from which new polyps are budded off. This 

 formation of stolons agrees exactly with that met with in Cornnlaria. In some species 

 the base of the polyps broadens out into a membrane which unites the individuals 

 together. In this case the base of the calyx gives origin to endodermal tubes, which 

 anastomose on the liasal membrane, and thus connect the alimentary cavities of the 

 various polyps. The calyces are always seated upon the stolons or upon the basal 

 iiembrane, and are never sunk into them as in Antlidia or Sympodium. The polyps 

 usually arise at relatively great intervals from one another. It may happen, however, 

 that two arise close together ; or, as a rai-e case, one polyp arises at the base of the calyx 

 of another, so as to produce the social condition .so well seen in Telesto. But even 

 then the alimentary cavity of the bud is not in direct connection with that of the polyp, 

 being only united to it by fine nutritive canals which ramify from the wall of the calyx. 



The S2:»ecies as yet known are not numerous ; of those provided with stolons 

 Clavularia viridis, Quoy and Gaim., from Vanikoro in the Pacific Ocean, was the first 

 described. Clavularia [Cornularia, ^lilne-Edw.) crassa, ^I.-Edv,-., from the Mediter- 

 ranean, was described in detail by Kowalevsky and Marion.^ By the same authors a 

 second Mediterranean species was distinguished as Clavularia petricola'. The species 

 in which the polyps are united by a basal membrane are Clavulai'ia riolacea, Qiiuy and 

 Gaim., Clavularia rosea, Studer, and the northern forms Clavidaria horealis, Koren 

 and Danielss., Clavularia arctica, Koren and Danielss., and Clavularia stornu, 

 Koren and Danielss. As not belong-ing to the o-enus Clavo.lai-ia may be mentioned 

 Clavularia. riisei, Duch. et Mich., and Clavularia prolifera, v. Koch. Both these 

 lieloug to the genus Telesto, Lamx. 



The species of Clavularia, in whirh the individuals are united by stolons, are in 

 habit very like those of Cornxdaria. On this account Milne-Edwards refers the 



' Ann. Mus. Hist. Xat. de Mar.-eille, p. 9. 



