548 
ECHINODERMATA. 
communication with the intestines and respiratory organs. They 
have neither head, eyes, nor articulated feet, their organs con¬ 
sisting only in tubes or pores, or orifices for the transmission of 
water. Their members of motion are very imperfect, and their 
nervous system can be but indistinctly traced. They are all 
marine, and quickly regenerate any of their parts that are separ¬ 
ated from them. 
Section I. —Fistulides. 
With a soft mobile and irritable epidermis, and an elongated, 
cylindrical, soft and contractile body.—It has four genera; viz* 
1. Sipunculus ; 2. Priapulus; 3. Fistularia; and 4. Holothuria. 
Genus FISTULARIA.— Lamarck. 
Generic Character .—Body cylindrical, soft and free; skin 
coriaceous, extremely rough, and covered with tubercles ; mouth 
terminal, surrounded with dilated tentacula at the summit, the 
depressed part divided or dentated; anal orifice at the posterior 
end. 
Section II. —Echinides. 
Animals protected by an immoveable solid crust; body de¬ 
pressed or globular, without any radiating contractile lobes •, anal 
orifice distinct from the mouth ; spiniferous tubercles fixed im¬ 
moveable on the shell, but having moveable spines.—It has 
eleven genera; 5 . Cidarites ; 6. Echinus; 7. Nucleolites; 8 . 
Cassidulus; 9. Spatangus ; 10. Ananchytes; 11. Galerites; 
12. Echinoneus; 13. Fifularia; 14. Clypeaster; 15. Scutella. 
Genus 6.—ECHINUS.— Linnaeus. 
With a regular, globular, orbicular, or oval body; with a solid 
setaceous covering; beset with imperforate tubercles; upon which 
are articulated moveable spines; shell consisting of five com¬ 
partments, each having a multiporous diverging margin or band, 
which extends in a radiate form from the summit to the mouth ; 
mouth central, placed below, and protected by five long ena¬ 
melled pieces, set in a conical form ; anal orifice above. 
Echinus esculentus .— The Edible Sea Urchin. 
Plate XCV. fig. 7. 
With a hemispherical globose shell, having porous bands, and 
