164 



TUK ANN'ELIBES. 



«§. 154. 



entirely distirii't from tlie rest of the body.*''' Tl^ese suckers seeve not only as 

 loooniotive 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 Ilirudinei 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 tin; blood. Witli BrnnchiohdeUa, the 

 pharynx has horny upper and lower jaws, of a pyramidal ibnn.'^* AVith San- 

 guisuga, and llaetnojns, on the contrary, the base of the pharynx has thi'ee 

 fleshy swellings, the projecting arciibrm 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 as a proboscis.*"' With 

 the Abranchiati, and Capitibrantihiati, 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 fddcd upon itself, and 

 project far out of the mouth.'" With many Annclides, the pharyn.x 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.*'-" 



//. Intestinal Canal. 



§154. 



The intestinal canal of the Neraertini passes directly from the mouth to 

 the anus, without forming a stomachal dilatation. Its walls are closely 

 united with the parenchyma of the body, audits internal surface throughout 

 i.-i thickly set with annular folds, which, projecting far into the canal, form 

 there pouch-like divisions.*" 



■'< PiarJcotn., and Pontobdella. 



4 See Henle, Muller's Arch. 1835, p. 575, Taf. 

 XIV. iig. 1. 



•'' S;>L" Moquin-Tandon, Monog. des Ilirud. p. 

 iA, VI I. (is. 2. 11, in. IV. v. ; Brandt, Aled. Zr>ol. 

 H. r. 215, Tiif. XXIX. A. fig. 13-lS, 21, Taf. 

 X.XT.V. B. fig. 13-17. The sweUiugs of these 

 li^cchHS are carried in front during suction, so as 

 til riii'Mnhle a three-rayed star — the form of tlie 

 wound wliich tiiey ]iroduce. 



G See MoiHtn-Tandon, loc. cit. PI. IV. This 

 (iroboseis quite reminds one of the jiharyngeal tul>e 

 of the i'/nHariae, which also can be protruded from 

 the muuth, but without being reversed. 



^ This pharyngeal tube is short with Amphi- 

 nome, tfereix, Eiivire, iin.l I'rripafuft ; but very 

 long with Ap/iroditr, Poh/nor, Hesionr, Phyllo- 

 done, G/i/cera, and Go/i/adfl ; see AuUouin and 

 Milne Edwardx, Recherches, &c.,loc. cit. That of 

 Aphrodite, Polynoe, Amphinome, and others, 

 has been regarded as a stomach ; »ee Treniranus. 

 in Tiedemann^s Zeitsch. f. Phys. III. p. 161. Taf. 

 XII. fig. 9. 10, k ; Grube, Zur Anat. d. Kiemen- 

 wiirmer p. 54, et seq. and Stanniun, Isi3, p. 982. 

 But the popition, structure and muscular appara- 



tus of this organ are ai:ainst this view, and quite in 

 favor of its being a pharynx. 



** The jaws are wanting with Amphinome, Phyl- 

 lodoce, Aricia, Chaetopterus, ai.d Arenicola. 



y There are two strongly-curved Jaws with Ne- 

 reis, Lycastis, and Peripat'ix ,- f >\\r with Polynoc, 

 Aphrodite, and G/ycera ; and ei:;iit with Luwbri- 

 nereis. Of the seven with F.niiirc, there are 

 four, one on one side, and three on the other. The 

 same asymmetry exists with those of As/aura and 

 Oenone ; see Audouin and Mihie Edwards, Re- 

 cherches, kc, loc. cit. 



1 According to Riithki (Danzig. Schrift. loc. cit. p. 

 96), these transverse fulds dn not exist with Rorlaxia 

 striata, except when the body is shortened by con- 

 traction, and they disapijear when it is again extend- 

 ed. But it did not apii.ar thus to me with the nu- 

 merously folded intestine of Meclcelia aniiulata. 

 lie lie Chiaje had already observed these folds 

 with Pnlin sipuncu/us, but figured them as iso- 

 lated pouches (Memorie, loc. cit. II. p. 407, Tar. 

 XXVIII. tig. 3, 6, or Isis, 1S32, Taf. X. fig. II. 3, 

 4). .According to (^uatrefases (Ann. d. Sc. Nat. 

 VI. 1846, p. 243), the intestinal canal of the 

 Nemertini. which occupies the a.^ts of the body, 



