MOLLUSCAo 201 



with extraneous bodies, or inclosing such. The branchial 

 orifice has four rays, the anal one the same, or divided trans- 

 versely. The branchiae are divided longitudinally into per- 

 sistent regular deep folds. 



a. Body pedunculated. 



The peduncle, in this division, may be said to have its 

 rise in the summit of the body, which it serves to suspend. 



The abdomen is lateral. The meshes of the branchiae 

 are destitute of papillae. 



GENUS BOLTENIA. The tentacular filaments of the 

 branchial circle are compound. There is no liver, and the 

 ovarium is compound. Only one species is known, B.fusi- 

 forme. Savigny, Mem. tab. i. f. 1., and tab. v. f. 5. It is 

 the Vorticella Bolteni of Lin. and the Ascidia Clavata of 

 Shaw. 



b. Body sessile. 



M. Savigny describes this group as a genus, which he 

 terms Cynthia, which he divides into four sub-genera. 



(A.) Tentacular filaments of the branchial orifice com- 

 pound. The folds of the branchiae more than eight in num- 

 ber. The liver distinct, and surrounding the stomach. 

 Ovarium divided, with one division at least on each side the 

 body. The intestine destitute of a rib. 



GENUS CYNTHIA Meshes of the branchiae unchanged 

 by the folds. C. Momus. Sav. tab. i. f. 2. 



GENUS COZSIRA Meshes of the branchiae interrupted 

 by the folds. C. Diona of Sav. tab. vii. f. 1 . The Ascidia 

 quadridentata of Forskal. 



(B.) Tentacular filaments of the branchial orifice simple. 

 The folds of the branchiae eight in number, four on each 

 side, and the meshes uninterrupted. Intestine strengthen- 



