CORALLIFERI. 517 



covering various bodies, and sometimes forming stems or leaves, of which, 

 in certain species, one side only is furnislied with cells, and in others, both: 

 tlieir substance is more or less corneous. 



Cellepora, Fab. 



Masses of small calcareous vesicles or cells, crowded one against the other, 

 and each perforated by a little hole. 



TuBULiPORA, Lam. 

 Masses of little tubes, of which the aperture is as wide as the bottom, or 

 wider. 



Bodies exist in the ocean that resemble the Corals of which we 

 have been speaking, both in substance and their general form, but 

 in which Polypi have not yet been discovered. Their nature is 

 consequently doubtful, and great naturalists, such as Pallas and 

 others, have considered them as plants; others, however, consider 

 them as having very small cells, and as being inhabited by coralli- 

 ferous Polypi. In this case they belong to the present order. 

 Those, in which the interior is filled with corneous threads, still 

 present some analogy to the Ceratophyta. In the 



COKALLINA, Lin. 

 We observe articulated stems placed on species of roots, and divided into 

 branches, also articulated, on the surface of wluch no pores can be seen, 

 and in which no Polypi have hitherto been discovered. 



C. officinalis^ L. The bottom of the sea on certain coasts is completely 

 covered with this coral, the joints of which are ob oval and the ramusculi 

 arranged like pinnate leaves, bearing other branches similarly disposed. 

 It is white, reddish, or greenish. It was formerly employed in pharmacy 

 on account of its calcareous nature. 



Of all these productions without apparent Polypi, which are conjectur- 

 ally referred to the Coralliferi, few are more singular than the Acetabula, or 



Acetabulum, Lam. 

 Where we find a slender and hollow stem supporting a round tliin plate, 

 like a parasol, with radiating stria:, crenulated at the edge and having a lit- 

 tle smooth disk sun-ounded with pores in the centre. No Polypi can be 

 discovered in them. The rays of the disk are hollow and contain greenish 

 granules, a circumstance which led Cavolini to consider them as plants. 

 One of them — Tubularia acetabulum, Gm., is found in the Mediterranean. 



