75 



arrangement, eight species, placed by^Gmelin under this 

 genus, besides the fossil species radians and ramulosa,'^ are 

 removed, and no other genus proposed for their reception. 



The chief generic character of these animals, as derived 

 from their ascertained structure, is, that the animal sub- 

 stance contained in each tube so communicates v/ith the 

 whole mass by an intercurrent organization, as to render it 

 one connected system ; and, by retaining the original ar- 

 rangement of the perspicacious Linnseus, with a very small 

 change in his definition, the genus will be found sufficiently 

 distinct and comprehensive ; and the several species, the 

 structure of which is known, will be characterized by the 

 diiFerent modes of organization by which this communi- 

 cation is effected. 



Tiibipora. — A stony polypifer formed by cylindrical 

 tubes, communicating laterally with each other. 



Sp. 1. T. musica. — Formed by erect, cylindrical, parallel, and dis- 

 tinct geniculated tubes, containing an internal tubular orga- 

 nization, connected by small radiating tubuli passing through 

 the external tubes and the transverse plates, by which the 

 tubes are supported and united. 

 Recent. 



2. — radians, — With erect parallel tubes, including others, which, 



by radiating horizontally through the external tubes, connect 

 the whole. — Org. Rem. vol. ii. p. 13, PL i. frontispiece. 

 Fossil. 



3. — catenulata. — ^With erect, oval, parallel tubes, laterally porous, 



and placed in vertical laminse, which, by anastomosing, form 

 a chain-work. — AmcEn. Ac. Tab. iv. fig. 20. It is also re- 

 presented. Org. Rem. PI. iii. fig. 4, 5, 6. 

 Fossil. 



4. — axillaris. — With very short, distant, erect, cylindrical tubes, 



placed in the connecting angles of fiexuous vertical laminse. — 

 Millep. Serpens. Amoen. Ac. i. Tab. iv. fig. 26. 

 Fossil. 



Organic Remains, vol. ii. p. 13, PI. i. p. 18, PL iii. fig. 1. 



