UNIVALVES SABELLA. 199 



SABELLA Sabella. 



DESCRIPTION OF PLATE XXXVU 



Fam. 1. Fig. 1. S. alveolata. Fam. 1. Fig. 2. S. belgica. 



Fam. 1. Fig. 3. S. chrysodon. 

 Fig. 4. A fragment of a gigantic specimen of the preceding species. 



Shell tubular, composed of particles of sand, broken shells, and ve- 

 getable substances, united to a membrane h/ a ylntinous cement. 



THE coveriug of the animal of this very extraordinary 

 genus is composed of fragineuts and particles of different 

 marine and vegetable productions, adhering to a tubu- 

 lar membrane : some are detached, and others are affix- 

 ed by the base. The S. ammoniata is covered with 

 fragments of the Cornu-Ammonis; the S. Indica, with 

 particles of quartz; and the S.clavata, with various small 

 stones. The S. alveolata consists of numerous parallel 

 tubes, communicating by an aperture, forming when in 

 mass the appearance of an honey-comb ; the tubes are 

 nearly straight, and ft*om two to three inches long: it ad- 

 heres to rocks in extensive clusters. The S. rectangula 

 is one of the largest of the genus, and often measures 

 nine inches in length. 



The S. vegetabilis, and S. arundinacea are covered 

 with fragments of twigs, the bark of stems, and broken 

 pieces of the Tellina Cornea. 



The greater number of the species inhabit the rivers 

 and fresh waters of Thuringia and Belgium, and the 

 remainder the Indian, American, Northern, and Euro- 

 pean seas. 



Sabulum, whence Sabella is derived, signifies fine 



