202 Professor Link's Observations on Zoophytes, 



naria pavonia, of which he described the fruit ( Horce Bero- 

 linenses 7 ). Its position is near the Corallinece. 2d, Hali- 

 medea is articulated with compressed joints, interiorly cal- 

 careous, containiug a fibrous marrow which unites the 

 joints. The H. Opuntia ( Corallina opuntia, Linn. Flabellaria 

 opuntia, Lam.) has been carefully examined by Schweigger. 

 He observed the fibres to be succulent filaments, which in- 

 crease and ramify irregularly. The structure of the cellular 

 tissue is decided. He, therefore, concludes, that the C. 

 opuntia ought to be restored to the vegetable kingdom. 

 Its parenchyma is formed of pentagonal or hexagonal cells 

 as in plants, a structure which never occurs in animals. 

 Link has also examined this species, and agrees with 

 Schweigger. He finds, in addition, that the fibrous tissue, 

 which forms the middle layer of the articulations, is com- 

 posed of ramified leaflets as in an viva. These leaflets form 

 a membrane which receives the vesicular cells. These cells 

 rarely angular are not in contact with each other. They 

 do not constitute the membrane which contains them, as 

 we see in the superior kinds of plants. Thus the structure 

 of the H. Opuntia agrees with that of plants possessing a 

 complicated organization. But it approaches that of the 

 Algce, for the Halimedece may be considered as compound 

 ulvae, and the Fuci may be viewed as compound Confervce. 

 The calcareous deposit is formed in cells within the interior 

 of the plant, upon the two sides of the most internal fibrous 

 layer. 



Lamarck re-united the Dichotomaria with the Sertularice. 

 Lamouroux divided them into two genera, viz. Galaxaura 

 and Liagora. The first genus contains the true Dichoto- 

 maria, D. fragilis. The plants of this genus are much 

 ramified ; the articulations are rounded when first com- 

 pressed and traversed by irregular membranes when they 

 are dry. Both internal and external surfaces are covered 

 with calcareous matter, which does not exist at the first 

 period of their existence. 



When viewed carefully, small holes may be observed 

 irregularly spread, which, perhaps, permit the escape of the 

 seed as in Fuci. When the calcareous deposit is removed 

 by muriatic acid, by means of a magnifier, we see distinctly 

 that the whole mass of the vegetable consists of interlaced 





