242 NULLIPORA. 



sima, solida. Sitperjicies laevis, poris coiispicuis plerumquc 

 nullis." 



When a piece is steeped in a diluted acid, and the calcareous 

 matter removed, a soft membrane remains retaining the size and 

 figure of the original. Examined with a moderate magnifier, 

 this appears to be marked with close parallel striae crossed con- 

 centrically with others st little wider intervals, exhibiting just 

 such an appearance as Ellis has represented in prepared por- 

 tions of Corallina officinalis and Millepora lichenoides. If, how- 

 ever, a higher power of the microscope is used it will be seen 

 that these striae are all composed of nearly equal oblong cells 

 arranged in parallel lines, and laid in or upon the mucaginous 

 matrix on which the figure really depends. There are no 

 cells on the marginal line which is entirely mucaginous ; and 

 there are numerous minute granules immersed in that portion 

 of the matrix which contains the cells. (See Plate XXII. Fig. 8.) 

 It is very evident from this anatomy that this Nullipore is an 

 organic production ; and indeed there can be little doubt of its 

 being a state of the Millepora Uchenoides, which we have al- 

 ready described as mei-elv the basis of Corallina ofiicinalis. 



Nihil imitile, iiildl vamim, nihil supervacaneiiin in Natural" — Bacon 



