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 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 the blood. With Branchiobdella, the 

 pharynx has horny upper and lower jaws, of a pyramidal form.''*' With ^an- 

 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 as a 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 

 iiorny, 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 Caiial. 



§ 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.*" 



S Pincicola, and Pontobdella. tua of this or^an are against this view, and quite in 



* See lien/e, Muller^s Arcli. 1835, p. 575, Taf. favor of its being a pharynx. 



XIV. fig. 1. 8 The jaws are wanting with Amphino7ne, Phyl- 



5 See Moquin-Tandon, Monog. des Hirud. p. lodoce, Aricia, Chaetopterus, and Arenicola. 

 43, PI. I. fig. 2. 11, PI. IV. V. ; Brandt, Med. Zool. a There are two strongly-curved jaws with Ne- 

 ll, p. 245', Taf. XXIX. A. fig. 13-18, 21, Taf. rets, Lycastis,-A.viA Peripntus ;fmix\\h\\Polijnoe. 

 XXI.X. B. fig. 13-17. The swellings of these Aphrodite, and Glycera ; and tiirht with Ltimbri- 

 leeehes are carried in front during suction, so as nereis. Of the seven with Kiinire, there are 

 lo resemble a three-rayed star — the form of the four, one on one side, and three on tlie other. The 

 wound which they produce. same asymmetry exists with tliose of Aglaiira and 



6 See Moquin-Tandon, loc. cit. PI. IV. This Oenone ; see Audoiiin and Milne Edwards, Re- 

 proboscis quite reminds one of the pharyngeal tube cherches, &c., loc. cit. 



of the P/anarjae, which also can be protmded from 1 According to Rnthk^ (Danzig. Sclirift. loc. cit. p. 



the mouth, but without being reversed. 96), these transverse f ilds do not exist with Borlasia 



7 This pharyngeal tube is short with Amphi- striata, excejit when tlic body is shortened by con- 

 no fnc, Nereis, Eunice, and Pe.ripatus ; but very traction, and tin y <iisa]ipear when it is again extend- 

 long with Aphrodite. Pnh/noi, Hesione, Phyllo- ed. But it did not a|ipear thus to me with the nu- 

 dor.e, Glycera, a.m\ G on iada ; sec Audouin and merously fnUUd intestine of Mecke/ia annulata. 

 Mi'/nc JEfZujarii.s, Recherches, &c., loc. cit. That of Delle Chinie had already observed these folds 

 Aphrodite, Po/ynoe, Amphinome, and others, with Po/m x//))(»ri//»x, but figured them as iso- 

 has been regarded as a stomach ; see Treviranus. lilted i)()ucties (.Meniorie, loc. cit. II. p. 407, Tav. 

 In Tiedemann's Zeitsch. f. Phys. III. p. 161. Taf. XXVIII. fig. 3, 6, or Isis, 1832, Taf. X. fig. II. 3, 

 XII. fig. 9. 10, k ; Grube, Zur Anat. d. Kiemen- 4). According to (^uatrefagcs (Ann. d. Sc. Nat. 

 warmer p. 54, et seq. and Stannius, Isis, p. 982. VI. 1846, p. 243), the intestinal canal of the 

 But the position, sti'ucture and muscular appara- Nemertioi, which occupies the axis of the body. 



