CLASS CIRRHOPODA. isi 
Their base is usually formed of a calcareous lamina, and fixed 
to various bodies. The four valves of their operculum close 
the orifice exactly. 
The rocks, shells, &c. of all our coasts are, in a manner, 
covered with a species of balanus, the Zepas balanus, L., 
Chemn. VIII. xcvii. 826. Naturalists have separated from it 
The Acasta, Leach, whose base is irregular, convex 
towards the exterior, and which does not become fixed. 
Most of them are found in sponge. (Acasta Montaguz, Leach.) 
The Coni#, Blainv.; the tube of which has but four 
salient pieces. (Conta radiata, Blainv.) 
The ASAM2, Ranzani, where the tube has no decidedly 
salient pieces. (Lepas porosus, Gm.) 
The PyrGom#, Savig., whose tubular part, forming a 
strongly depressed cone, has but a very small orifice, almost 
like the shell of a fissurella. (Pyrgoma cancellata, Leach.) 
The OcTHos1®, Ranzani, which have but three salient 
pieces in the tube, and only two valves to the operculum. 
(Lepas stremii, Mill. Zool. Dan.) 
The Creusia, Leach, with four salient pieces and two 
valves to the operculum. (Creusia spinulosa, Leach.) 
M. de Lamarck, under the name of CORONULZ, separates 
the very wide species, where the parietes of the cone are occu- 
pied by cells: so large that they resemble chambers. (Lepas 
balenaris, L., &c.) And under that of 
_ TUBICINELL&, those in which the tubular portion is 
elevated, narrower near the base, and divided into annuli, 
which mark its growth. (The Tubicinella, Lam., Ann. du 
Bind. To xcx., 1, 2;) 
There are some species of these last two subgenera which 
affix themselves to the skin of the whales, and even penetrate 
into their blubber. 
To the preceding subgenera must be added the 
