14 ZOOPHYTES. 



Plate II. — Flustra Carbasea. 



Fig. 24. Nascent Flustra wherein both hydrre had decayed. 



25. Nascent Flustra having generated a third hydra while the second 



subsisted. 



26. Young Flustrse become foliaceous. 



All the figures except the first and last are enlarged. 



§ 2. Flustra foliacea. — Plates III., IV. — The leading features of 

 the preceding paragraph, as illustrating the general history and character 

 of this tribe of zoophytes, may be kept in remembrance along with further 

 prosecution of the subject, by a few observations on another species. 



The Flustra foliacea rises above five inches high, by a flat, narrow 

 stem, and diverges to a still greater extent in breadth by subdivisions, all 

 in the same plane, and tending to dichotomous arrangement of the parts. 

 This pecular formation is satisfactorily demonstrated by their extremities, 

 the whole of which are bounded by curvatures. Like the former, the 

 Flustra foliacea may be compared to a single large leaf, partitioned into 

 an indefinite number of subdivisions. It is somewhat thicker than writing 

 paper. — Plate III. 



Instead of a large and conspicuous specimen, rising singly from any 

 substance whereon it is founded, numerous smaller specimens sometimes 

 occur, within very circumscribed limits, which transient observation might 

 ascribe to a common stem, while each is a separate and independent pro- 

 duct. The Flustra foliacea generally grows erect and free, but, perhaps 

 from accidental adhesion, a portion occasionally spreads over the same 

 subjacent substance, whereon a specimen is rooted ; various nascent Flustra* 

 then springing vertically out of that spreading surface. Here the cell 

 consist of long and irregular hexagons, and are much better defined than 

 those of the leaves. 



Unlike the structure of the Flustra carbasea and Murrayana, both 

 sides of the foliacea are wholly composed of cells, which, in general, bear 

 some resemblance to a longitudinal section near the middle of a pear. At 

 the wider end, two short obtuse white spines stand on the opposite edges 



s 



