CYNTHIA AGGREGATA. CYNTHIA AMPULLA. 451 



quadrangular orifices rise from the surface, while the 

 radicles below, gradually attenuating, disappear from 

 view. A complete metamorphosis has been accom- 

 plished; the Spinula has become changed into an 

 Ascidian resembling the Cynthia aggregata, so fre- 

 quently met with upon our coasts. 



The CYNTHIA AGGREGATA is the most common of 

 any of the tribes occupying our seas. Almost every 

 substance becomes readily, and often profusely in- 

 vested by it. Vegetables, zoophytes, wood, shells, rocks 

 and stones serve alike for its abode, and upon these it 

 fixes itself, either solitarily, or associated in groups. 

 It is an elegant, and, at all events, a harmless occu- 

 pant of the aquarium, requiring but little attention 

 except during the summer months, at which season, 

 whoever is desirous of tracing the history of the 

 Spinulse and their strange metamorphosis, should 

 .attentively watch for their appearance. There is an 

 old Spanish proverb, which says, " Lo que no acaece 

 en un ano, acaece en un rato," What does not 

 happen in a year may happen in an instant; and 

 accordingly, during the months of June and July, a 

 few specimens of these Ascidians, kept apart in small 

 vessels, should from time to time be carefully ex- 

 amined with a lens, and their offspring transferred 

 to watch-glasses for the purpose of microscopic 

 examination. 



The CYNTHIA AMPULLA, "The Woolly Ascidia" un- 

 like the generality of the race, is not affixed by the base 

 to any foreign substance; it is free. Its dwelling is 

 in deep water, among sand at the bottom of the sea, 

 and it is usually caught by the lines of the fishermen; 



