Dr. F. Miilier on Balanus armatus. 395 



about a fathom below the level of the water at midtide, on an 

 isolated rock (not far from the shore at the south end of the 

 Praia de Fora), and forms dense, slightly branched bushes of 

 as much as 0*15 metre in height. The Hesh-coloured stem of 

 this polype, about 2 millims. in thickness, is usually coated 

 by a dark-yellow sponge with pin-like siliceous spicules, form- 

 ing a thin crust ; and Balanus armatus is rarely absent from 

 such sponge-coated polyparies : as many as ten or twelve are 

 frequently seated, closely pressed together, upon such a poly- 

 pary ; and these are likewise covered by the sponge up to the 

 opening. 



On the same rock four other Balanid^ reside : — uppermost, 

 above midwater, Chthamalus stellatus; at the lower limit of 

 this species, and usually closely covered by it, Tetraclita i^o- 

 rosa, especially on the seaward side 5 a little lower are seated 

 some large shells of Balanus tin'innabulum ; and then follows, 

 extending down into the domain of the Carijoa, which is 

 domiciled on the landward side of the rock, Balaiius impro- 

 visus, var, assimilis. The latter occurs also in single speci- 

 mens seated on the Garijoa and sometimes on Balanus armatus^ 

 or serving as a support for the latter. Once only I found a 

 small B. tintinnahulum^ only 8 millims. in height, upon the 

 Garijoa. 



Sometimes, but rather rarely, B. armatus is found attached 

 to rocks. On one occasion I found two of its shells, in com- 

 pany with numerous specimens of B. imrprovisus^ var. assimilis ^ 

 upon a living Purpura. Lastly, I possess two specimens 



tlie same level : the great majority of these remain short (about 4 millims. 

 in length) and simple ; but some become elongated, and again put forth 

 lateral branchlets. The branches and branchlets perfectly resemble the 

 stem in their structure. Each of them bears a polype at its extremity, and 

 is traversed by its body-cavity. The body-cavities of the individual po- 

 lypes which, as stem, branches, and branchlets, compose the polypary, 

 are not connected with each other. From the lower extremity of the 

 stem issue some thinner tubes, which act as roots, and, when applied to 

 flat surfaces, are often flattened and dilated. Sometimes two neighbour- 

 ing branches grow together superficially ; this takes place more frequently 

 in the roots. When exposed to the light, the dried polypary is very ra- 

 pidly and completely bleached. Even in the fresh state, individual poly- 

 paries are almost colourless ; but others are, on the contrary, much darker 

 than is shown in the figure. The name Carijoa is derived from that of 

 the inhabitants of our island (Santa Oatharina) at the time of its disco- 

 very by Europeans, — the Carijos. 



Besides the yellow coat [mentioned in the text], four or five species of 

 Reniera are found, but not very frequently, adhering to the Carijoa ; these 

 are of a dark-red, pale-violet, greenish-grey, or snow-white colour ; and 

 one can imagine nothing of a gayer appearance than a bush of Carijoa 

 such as I have seen, traversed and enveloped by all these sponges at the 

 same time. 



28* 



