6 POPULAH BRITISH CONCHOLOGY. 



open mouth, ready to suck in any microscopic food which 

 the currents may chance to bring within reach. If these 

 creatures were endowed with the gift of memory however, 

 each one might recall a time in his existence when he was 

 much more active and bright, for, like all his tunicated 

 brethren, he began life as a merry tadpole, frisking about 

 with tail and arm-like projections, his body light and trans- 

 parent, and his motions free; bat alas ! 



" The light of other days is faded ;" 



for one day he seized a rock or a weed with his arms, and 

 did not let go till they became rooted to the surface ; then 

 throwing off his tail as no longer of use, he assumed his 

 present state of otmm cum dignitatej and a new shape 

 altogether. 



The smooth, bright orange species of Cynthia, figured in 

 both states (Plate I. fig. 2 a, h), will present one of the very 

 various forms contained in this section. 



The Tunicata are divided into the following five fa- 

 milies : — 



1. BoTRYLLiD^. Several animals enclosed in one body. 



Ex. ApUdium fallax, Plate I. fig. 3 ; Botryllus poly- 

 ci/clus, Plate I. fig. 6. 



2. Clavellinid^. Several animals with independent bodies 



