164 THE ANNELIDES. $ 154, 
entirely distinct from the rest of the body.© These suckers serve not only as 
locomotive organs, as the one, for instance, which is situated at the posterior 
end of the body, but also for the drawing in of liquid food, and particularly 
blood.- For this purpose, many Hirudinei have a short and spacious pha- 
rynx, possessed of muscular walls, which are blended with the parenchyma 
of the body, and which are armed with horny teeth, by which they cause 
the wounds necessary for sucking the blood. With Branchiobdedia, the 
pharynx has horny upper and lower jaws, of a pyramidal form.” With San- 
guisuga, and Haemopis, on the contrary, the base of the pharynx has three 
fleshy swellings, the projecting arciform border of which is edged with bicus- 
pid teeth. In this respect, Clepsine is quite different. The pharyngeal 
tube is very long, and from its base a movable fleshy tube can be protrud- 
ed out of the mouth, and which the animal can use asa proboscis. With 
the Abranchiati, and Capitibranchiati, the pharynx is simple, short and 
muscular, and presents nothing remarkable. With the Dorsibranchiati, it 
is very muscular, of variable length, and stretches freely into the cavity of 
the body. By the aid of special muscles, it may be folded upon itself, and 
project far out of the mouth.” With many Annelides, the pharynx has a 
horny, masticatory apparatus of sometimes a very complicated structure, 
and which, when the pharynx is protruded, often extends out beyond it, and 
serves as a prehensile organ.© These two, four, seven, eight or nine jaws 
always move laterally upon each other. They are usually curved like 
hooks, and denticulated upon their concave side. When numerous, they 
are of dissimilar forms with the same individual. 
IT. Intestinal Canal. 
§ 154. 
The intestinal canal of the Nemertini passes directly from the mouth to 
the anus, without forming a stomachal dilatation. Its walls are closely 
united with the parenchyma, of the body, and its internal surface throughout 
is thickly set with annular folds, which, projecting far into the canal, form 
there pouch-like divisions. 
8 Piscicola, and Pontobdelia. tus of this organ are against this view, and quite in 
4 See Henle, Muller's Arch. 1835, p. 575, Taf. 
XIV. fig. 1. 
5 See Moquin-Tandon, Monog. des Hirud. p. 
43, Pl. I. fig. 2.11, Pl. IV. V.; Brandt, Med. Zool. 
Il. p. 245, Taf. XXIX. A. fig. 13-18, 21, Taf. 
XXIX. B. fig. 13-17. The swellings of these 
leeches are carried in front during suction, so as 
to resemble a three-rayed star —the form of the 
wound which they produce. 
6 See Moquin-Tandon, loc. cit. Pl. IV. This 
proboscis quite reminds one of the pharyngeal tube 
of the P/anariae, which also can be protruded from 
the mouth, but without being reversed. 
7 This pharyngeal tube is short. with Amphi- 
nome, Nerets, Eunice, and Peripatus ; but very 
long with Aphrodite, Polynoé, Hesione, Phyllo- 
doce, Glycera, and Goniada; see Audouin and 
Milne Edwards, Recherches, &c., loc. cit. That of 
Aphrodite, Polynoé, Amphinome, and others, 
has been regarded as a stomach ; see T'reviranus. 
in Tiedemann’s Zeitsch. f. Phys. III. p. 161. Taf. 
XIU. fig. 9.10, k; Grube, Zur Anat. d. Kiemen- 
wirmer p. 54, et seq. and Stannius, Isis, p. 982. 
But the position, structure and muscular appara- 
favor of its being a pharynx. 
8 The jaws are wanting with Amphinome, Phyl- 
lodoce, Aricia, Chaetopterus, and Arenicola. 
9 There are two strongly-curved jaws with Ve- 
reis, Lycastis, and Peripatus ; four with Polynoé, 
Aphrodite, and Glycera ; and eight with Lumbri- 
nereis. Of the seven with Eunice, there are 
four, one on one side, and three on the other. The 
same asymmetry exists with those of Aglaura and 
Oenone ; see Audouin and Milne Edwards, Re- 
cherches, &c., loc. cit. 
1 According to Rathké (Danzig. Schrift. loc. cit. p. 
96), these transverse folds do not exist with Borlasia 
striata, except when the body is shortened by con- 
traction, and they disappear when it is again extend- 
ed. But it did not appear thus to me with the nu- 
merously folded intestine of Meckelia annulata. 
Delle Chiaje had already observed these. folds 
with Polia sipunculus, but figured them as iso- 
lated pouches (Memorie, loc. cit. Il. p. 407, Tav. 
XXVIII. fig. 3, 6, or Isis, 18382, Taf. X. fig. IT. 3, 
4). According to Quatrefages (Ann. d. Sc. Nat. 
VI. 1846, p. 243), the intestinal canal of the 
Nemertini, which occupies the axis of the body, 
