435 



CLASS VI. 



CIRRHOPODA(l). 



[Lepas and Triton, Lin.] 



The Cirrhopoda, in several points of view, are intermediate 

 between this division and that of the Articulata. Enveloped 

 by a mantle, and testaceous pieces which frequently resemble 

 those seen in several of the Acephala, their mouths are fur- 

 nished with lateral jaws, and the abdomen with filaments named 

 cirri, arranged in pairs, composed of a multitude of little 

 ciliated articulations, and corresponding to a sort of feet or- 

 fins similar to those observed under the tail of several of the 

 Crustacea. Their heart is situated in the dorsal region, and 

 the branchise on the sides ; the nervous system forms a series 

 of ganglions on the abdomen. These cirri, however, may be 

 considered as analogous to the articulated appendages of cer- 

 tain species of Teredo, while the ganglions in some respects 

 are mere repetitions of the posterior ganglion of the bivalves. 

 The position of these animals in the shell is such, that the 

 mouth is at the bottom and the cirri near the orifice. Between 

 the last two cirri is a long fleshy tube, that has sometimes, but 

 erroneously, been taken for their proboscis, and at the base of 

 which, near the back, is the opening of the anus. Internally, 



(1) M. Delamarck has changed this name into Ciuripeda,. making- it a class. 

 M. de Klainville also makes a class of them, but he changes the name to Nestato- 

 poDA, and places them with the Chitones, in what he calls his type of the Malex- 

 tozahta. 



