400 Div. 3. ARTICULATA.— ANNELIDES. Class 1. 



M. Moquin Tandon has described a subgenus by the name of Aulastoma, the mouth of which has 

 merely longitudinal folds, several in number. 



In the suite of Nephelis, should be placed the Branchiobdellia of M. Odier, remarkable lor having 

 two jaws and no eyes. 



One species only is known, which lives upon the gills of the Crab. 



All these subdivisions have the anterior sucker a little separated from the body : the two next are 

 distinguished by a further separation, composing almost a segment, having a transverse aperture. 



HiEMocHARis, Sav., 



In addition to this conformation, have eight eyes, a slender body, and rings not very distinct. Their 

 jaws do not project, and are scarcely visible : they do not swim, but advance in the manner of the 

 caterpillars termed geometrical, and attach themselves particularly to fishes. They are the Piscicola 

 of Blainville, and the Icthiobdella of Lamarck. 

 One species is common upon the Carp, (//. piscium, Linn.). 



Albiones, Sav. {Pontoldella, Leach and Blainville), — 

 Diifer from the preceding by having the body bristled with tubercles, and eyes only six in number. 

 They live in the sea. 



There is a parasite on the Torpedo, named Branchellion, very similar to a Leech, but which appears 

 to have a little moutli at the hind border of its anterior disk, which last is borne on a slender neck, and 

 at the base of it is a small hole for the generative organs. The lateral edges of its folds, which are 

 compressed and salient, have been regarded as branchiae, but I cannot perceive vessels ramifying upon 

 them ; the epidermis is ample, and envelopes the creature like a very loose sac. 



Clepsines, Sav. {Glossoporis, Johnson), — 

 Ranks commonly also among the Leeches. The body is widened, with a disk only behind, and the 

 mouth is formed into a trunk, and not suctorial ; but it is not impossible that some of these belong to 

 the family of Planarice. PhilUnes, Oken, and MalacoldeUis, Blainv., have also a widened body, and 

 want the anterior sucker. Their habits are parasitic. 



The Gordians {Gordius, Linn.). — 

 Have the body in form of a filament ; slight transverse folds, which mark the articulations only ; and 

 no feet, branchiaj, or tentacles have yet been discerned ; nevertheless, they are internally distinguished 

 by a knotted nervous chord. They should perhaps be placed, however, with the intestinal worms, 

 Buch as the Nemertes. 



The various species inhabit fresh water, mud, and inundated grounds, which they perforate in all directions, 

 &c. [We have not unfrequently met with them upon garden-cabbages, and their name is derived from tlie com- 

 plex knots into which they seemingly entangle their ex- 

 tremely elongated bodies.] The commonest (G. aquaiicus, 

 Linn.), is several inches long, and scarcely thicker than 

 a hair. See the memoir of Dr. George Johnston on this spe- 

 cies in the Magazine of Natural History, vol. ix. p. 359.] 

 [This animal, which is found in slowly-running and stagnant 

 waters in the summer, is commonly mistaken for the species 

 Fig. 209.-G«rdiu3 aquaticus. "^ Filaria, the proper habitat of which is the intestines of 



Beetles and other insects. The head of Gordius is obtusely 

 conical, with a simple circular terminal pore for a mouth, from which a sort of membrane can be forced by 

 pressure. Tlie tail is bifid ; the processes short, equal, and ohtuse ; the latter has often been mistaken ft>v the 

 mouth. Thus DrTurtcn describes the mouth as "small, horizontal, with equal obtuse jaws." Dr. Johnston 

 states, that having cut off portions of the anterior extremity and tail, the detached parts soon lost every sign of 

 life ; it has, however, been asserted, that each part would grow into a perfect animal.] 



