510 CLASS ECHINODERMATA. 
MopsEA, 
The bark of which is thinner, and more adherent. (Isis di- 
chotoma, Seba, &c.) 
MADREPORA, Lin., 
Have their stony part sometimes branched, sometimes in 
rounded masses, or in extended lamine, or in leaflets ; but 
always furnished with lamellae, which are united concentri- 
cally in points where they represent stars, or which end at lines, 
more or less serpentine. In the living state, this stony part 
is covered with a living bark, soft and gelatinous, and bristling 
with rosettes of tentacula, which are the polypi, or rather the 
actiniz, for they have generally several circles of tentacula, 
and the stony lamine of the stars correspond, in some re- 
spects, to the membranaceous laminz of the body of the acti- 
nie. The bark and the polypi contract upon the slightest 
touch. 
The varieties of their general form, and of the figures which 
result from the combination of their lamellz, have given rise 
to several subdivisions, many of which, however, enter one 
into the other. They cannot be definitively established, until 
the relations of the polypi, with these dispositions, shall be 
known. 
When there is but a single circular star, or in an elongated 
line, with very numerous laminz, these are the Funeta, La- 
marck. Mad. fungites, L. Their animal truly represents a 
single actinia, with large and numerous tentacula, and whose 
mouth corresponds to the sunken part, where all the lamine 
end. 
We find among the fossils, stony polyparia, with a single 
star, which appear to have been free from all adherence. 
These are TURBINOLIA, Lamarck, Madr. turbinata, L. Cy- 
