PARENCHYMATA. 41? 



Several species inhabit the fresh waters in France *. 

 Others, and larger ones, are very abundant on the sea-coast 

 of tlie same country f . 



The surface of some seems pilose X- 

 Several are furnished anteriorly with two tentacula§. 

 M. Duges 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 tlie anterior ex- 

 tremity. 



It is to the first that I apju-oximate the Ph^enicurus, Rud., or 

 Vertumnus, Otto, in which there is but one orifice at the anterior 

 extremity. 



But one species is known — V. thetlddicola. Otto, Ac. Nat. 

 Cur., XI, part II, pi. 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. 



T^NIOIDEA. 



In our third family of parenchymatous Intestinal Worms, we place 

 all those species in which the head is provided Avith two or 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 



TAENIA, 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 lacfea, Zool. Dan., CIX, 1, 2; — PI. nigra, lb., 3, 4, and the other 

 species described by M. Duges, Ann. des Sc. Nat., X\''. pi. 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 theEncyc. Methodique. 



•f PI. aurantiaca, Cuv. 



X PI. hrocchii, Risso. 



§ PL cormda, Miill,, Zool. Dan., XXXII, 5, 7. Some of them are formed by 

 tearing the tentacula, under the eye of the spectator. The Planoch-es, Blainv., 

 belong to this division. 



II For its anatomy see Delle Chiaie, Memor,, I, pi. ii, f, 9, 6. 



