128 ANN ELIDES. 



ORDER I. 



TUBICOLJE * 



Some of the Tubicolse form a calcareous, homogeneous tube, proba- 

 bly the result of transudation, like the shell of the Mollusca, with 

 which however they have no muscular adhesion ; others construct one 

 by agglutinating grains of sand, fragments of shells and particles of 

 mud, by means of a membrane, also unquestionably transuded; the tube 

 of others again is entirely membranous or horny. To the first belongs 

 the genus 



SERPULA, Lin . 



The calcareous tubes of the Serpulae twine round and cover stones, 

 shells, and all submarine bodies. The section of these tubes is some- 

 times round, and sometimes angular, according to the species. 



The body of the animal is composed of numerous segments ; its 

 anterior portion is spread into a disk, armed on each side with seve- 

 ral bundles of coarse hairs, and on each side of its mouth is a tuft 

 of branchiae, shaped like a fan, and usually tinged with bright 

 colours. At the base of each tuft is a fleshy filament, one of which, 

 either on the right or left, indifferently, is always elongated, and 

 dilated at its extremity into a variously formed disk, which serves a 

 an operculum, and seals up the orifice of the tube when the animal 

 has withdrawn into it f . 



Serp. contortuplicatal, Ell., Corall., XXXVIII, 2. The most 

 common species ; its tubes are round, three lines in diameter, 

 and twisted. The operculum is infundibuliforum, and the bran- 

 chiae are frequently of a beautiful red colour, or variegated with 

 yellow, violet, &c. Vases or other objects thrown into the sea 

 are soon covered by its tubes. 



Serp. vermicular is, Gm. i Mull., Zool. Dan., LXXXVI, 7, 9, 

 &c. A smaller species, with a claviform operculum, armed 

 with two or three small points. The branchiae are sometimes 

 blue. No spectacle is more beautiful than that of a group of 

 these Serpulae when well expanded. They are found on the 

 coast of France. 



* M. Savigny adds the Arenicola to this order, and changes its name to SER- 

 PULACEA ; M. Lamarck, adopting his plan, converts the SERPULACEAinto SEDEN- 

 TARIA. The genera of my TuUcolee form the family of the AMPHITRITES, Savigny, 

 and those of the AMPHITRIT^EA and SERPULACEA, Lamarck. They form the order 

 ENTOMOZOARIA CHETOPODA HETEROCRISINA, Blainville, who, in defiance of his 

 own definition, places there SPIO and POLYDORUS. 



f The disk of the common Serpula heing funnel-shaped, has induced naturalists 

 to consider it as a proboscis, hut it is not perforated, and in all the other species it 

 is more or less claviform. 



J It is the same animal as the Atnphitriie penicillus, Cm'., or Pi-oloscidea, Brug., 

 or Probosciplectanos, Fab. Column. Aquat., c, xi, p. 22. 



