PARENCHYMATA. 417 
Several species inhabit the fresh waters in France *. 
Others, and larger ones, are very abundant on the sea-coast 
of the same country f. 
The surface of some seems pilose f. 
Several are furnished anteriorly with two tentacula§. 
M. Dugés separates from them the 
PRostoma, 
Where the anterior extremity is provided with an orifice, and the 
posterior with another. 
DERosToMA, 
Where the oral orifice is underneath, but nearer to the anterior ex- 
tremity. 
It is to the first that I approximate the PaHanicurus, Rud., or 
Vertumnvs, Otto, in which there is but one orifice at the anterior 
extremity. 
But one species is known—V. thethidicola, Otto, Ac. Nat. 
Cur., XI, part I, pl. xli, f. 2—a parasite of the Thethys fimbria; 
it is marbled, and frequently has a forked tail, so shaped by 
being torn ||. 
FAMILY III. 
TZENIOIDEA. 
In our third family of parenchymatous Intestinal Worms, we place 
all those species in which the head is provided with two cr four suck- 
ers placed around its middle, which is itself sometimes marked with 
a pore, and sometimes furnished with a little proboscis, naked or 
armed with spines. Sometimes there are four little trunks thus armed. 
The most numerous genus is 
Tania, Lin. 
The body of the Tape-worm is often excessively elongated, flat, com- 
posed of joints more or less distinctly marked, and narrowed anteriorly, 
where we generally find a square head hollowed by four small suckers. 
Observers have thought that they could perceive canals which 
arose from these suckers, and crept along the margin of the joints of 
* Planaria lactea, Zool. Dan., CIX, 1, 2;—Pl. nigra, Ib., 3, 4, and the other 
species described by M. Dugés, Ann. des Sc. Nat., XV. pl. iv. We find in Gmelin 
the long catalogue of this genus, which Miiller particularly has enriched; part of this 
savant’s figures are copied in the Encyc. Méthodique. 
t+ Pl. aurantiaca, Cuv. 
t Pl. brocchii, Risso. 
§ Pl. cornuta, Mill., Zool, Dan., XXXII, 5,7. Some of them are formed by 
tearing the tentacvla, under the eye of the spectator. The Planocéres, Blainy., 
belong to this division. 
\| For its anatomy see Delle Chiaic, Memor., I, pl. ii, f, 9, 5. 
