24 ZOOPHYTES. 



pression between two watch-glasses, a position rather difficult to be satis- 

 factorily effected, from the elasticity of the incurving edges. — Fig. 6. 



Only one side — the inner surface of the leaf — is cellular, wherein 

 this product approximates the Flustra carbasca. — Fig. 7. 



But the position of the cells is indistinct in front. — Fig. 8. They 

 are rather better defined behind, shewing them to be disposed collaterally, 

 in so many rows, across the leaf. The number of rows is determined by 

 the breadth of the leaf : I have not observed more than seven. 



Although the entire leaf consists of several parallel rows, a new cell 

 from the extremity sometimes prolongs its own individual row, while the 

 row on each edge affords no such extension by generation. Thence the edge 

 of the extremity is no longer even, but irregular. One of three rows, 

 issuing from the centre, its fellows on each side remaining stationary, 

 impairs the natural uniformity. 



An active, lively ascidian hydra, with fourteen tentacula, dwells here, 

 whose rise and fall distinctly expose the body through the thin sides of 

 the cell.— Figs. 7, 9, 10. 



I was long disappointed of a satisfactory result, from all the expe- 

 dients adopted for discovering the mode whereby this species of Flustra 

 was perpetuated, and what might be the aspect of the nascent animal. 

 This is invariably one most essential subject for illustration, in pursuing 

 the history of zoophytes, and, comparatively, seldom elucidated to the satis- 

 faction of the naturalist. 



Three specimens, obtained on September 24, were consigned to suit- 

 able vessels. Minute white corpuscula were swimming among the water 

 in one of them, two days afterwards, and many more on the 3d of Oc- 

 tober. When the vessel was emptied, a number of small, white, distorted 

 objects remained adhering to the side, just as high as the place which the 

 water had reached, therefore close to its surface. I conjectured them to 

 be originating Flustra?, as ultimately proved the fact. The vessel was, 

 therefore, replenished. 



It had been remarked of the planulse of the hydraoid zoophytes, first, 

 that they manifested a disposition to seek the light ; and next, that an 



