ZOANTHAIUA. 
1(57 
ments, many of which anastomose, so as to form arches and imperfect 
circles. The extreme segments are dilated and variously cut, some- 
times truncate, both sides being perforated with numerous pores just 
visible to the naked eye, and arranged in rows ; the pores circular, 
a nd level with the surface on the smooth and newly-formed parts ; hut 
m the older parts they form apertures of urceolate cells, which appear 
to be formed over the primary layer of cells, giving to the surface 
a roughish or angular appearance. The orifice is simple, contracted, 
with a very small denticle on one side ; the thickness of the branches 
varies from one half to two lines ; the interior is cellular ; the new parts 
ar e formed of two layers of horizontal cells, but the older parts are 
thickened by cells superimposed on the primary layers.” 
Millepora moniliformis is a species which attaches itself to the 
^ranches of the gorgons, and forms there a series of little rounded or 
lateral lobes. The animal is unknown, the cells very small, unequal, 
completely immersed, obsoletely radiate and scattered ; the polypier 
bxed, cellular within, finely porous and reticulated externally, extending 
111 to a palmated form. 
Of tuberous or wrinkled madrepores, which consist almost entirely 
°t fossil species chiefly belonging to the Silurian formation, we shall 
0l dy note Oyathophyllum as one of the best known species. 
There is no spectacle in Nature more extraordinary, or more worthy 
°t our a dmira tion than that now under consideration. These zoo- 
P%tes, whose history we are about to investigate— these wretched 
beings gifted with a half-latent life only — these animalcules so small 
ail( b so fragile — labour silently and incessantly in the bosom of the 
°cean, and, as they exist in innumerable aggregated masses, their cells 
a nd solid axes finish by producing in the end enormous stony masses. 
These calcareous deposits increase and multiply with such incalcu- 
able rapidity, that they not only cover the submarine rocks as with a 
Car Pet, hut they finish by forming reels, and even entire islands, which 
rise above the surface of the ocean in a manner remarkable at once for 
bbeir form and the regularity with which they repeat themselves. 
In noting the Indian and Pacific Oceans, navigators had long been 
struck with the appearance of certain earthy bases, which presented a 
conformation altogether singular. In 1G01, Pyrard de Laval, speak- 
of the Malouine (now the Falkland) Islands, said : “1 hey are divided 
