rosy- -pink ; when dry it fades to a yellowish; and when exposed to the 
sun becomes perfectly white, and rapidly crumbles to powder. Under the 
microscope, a longitudinal section (when the calcareous matter has been 
removed by acid) shows a series of concentrical zones, formed of oblong 
cells separated by narrow spaces, filled with granular cellules, or possibly 
the appearance of bands may arise from the remains of calcareous matter. 
Fig. 3. represents a section of this description. 
I follow Decaisne m referring the Nullipore of Lamarck to 
the Melobesie of Lamouroux, the latter name having been gene- 
rally adopted by such botanists as have described these pro- 
ductions, and the former by such zoologists as lay claim to them. 
Both names origmated im 1816, and whichever have priority, it 
must be a narrow question of months, which I am unable to 
decide. The species here figured would belong to Spongites of 
Kiitzing, and to Lithophyllum of Philippi; but does not appear 
in the list of Jelobesi@ given by Decaisne, nor yet, except under 
the more modern trivial name, decussata, im that of Endlicher. 
Nevertheless it is one of the earliest known species, as its nume- 
rous synonymes testify. 
The question of the vegetable nature of Coradlines, among 
which the Melobesie take rank, may now be considered as 
finally set at rest, by the researches of Kiitzing, Philippi, and 
Decaisne, whose various memoirs, particularly that of the last 
named, have thrown much light on this obscure department 
of natural history, and fully confirmed the early views taken 
by Peyssonel, the elder Jussieu, Pallas, &c., in opposition to 
those of Ellis and most succeeding authors, who have associated 
them with the zoophytes. Outwardly, deed, there is a striking 
resemblance, not less in form than in substance, between the 
Corallines and Corals ; but it is merely an outward resemblance. 
Whoever macerates a portion of one of these stony vegetables 
in weak acid, till the lime it contains be dissolved, will find that 
he has a structure of a totally different nature from that of any 
zoophyte, while it is perfectly analogous to that of many Alge. 
There is a near affinity, indeed, between the Coraline and the 
Rhodomelee ; or perhaps still more, the Condriee. 
Fig. 1. Mrtoprsia AGARICIFORMIS:—¢he natural size. 2. Portion of a 
lamina, with some of its epidermis removed, showing the banded arrange- 
ment of the cellules :—slightly magnified. 3. Longitudinal section of the 
same :—highly magnified. 
