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Show 462 ANNELIDES. The S IGALIONES, Aud • and Edw., have • a muc• h more• elo•n ga. ted form than t h eo th er Aphroditre·' each foot IS f.u rmshe·d wit.h c. 1rr1(.l ). The ,A.ooETES, Aud • and Ed w. ' are proVIded w1th ctrn whtch alternate w1· t h the elytra(2)·' their J. aws are stronger and more deeply dentated. · h' h · h b' A large species is found at the Antilles w 1c m a 1ts a tube of the consistence of leather( 3). This is the only situation we can as~ign to a new and very singular genus which I call CHJETOPTERUs, Cuv. h h e·1 The mout as n ther J. aws nor proboscis, and is furnished abo.v e w1· th a 11· p to w h1' c h are attached two ten. tacula. Ne. xt come·s a1 d' tsk W·l th nm· e pa·i rs o f {I'' eet , followed by a pa1r of long silky fasctcu 1 re- sembh· ng w·m gs. The lamellated bra.n chire. are rather b.e neath the body than above it, and extend along Its mlddl:-. . . . . Chretopterus pergamentaceus, Cuv. Tlus spcc~es, whtch 1s found at the Antilles, is from eight to ten inches m length, and inhabits a tube resembling parchment(4). (1) Sigalion Mathild83, Aud., and Edw., Littor. d~ la France, Annel. (2) .!J.coetes Pleei, Aud., and Edw., Collect. of the Museum. . (3) N n The Phyllodoce maxillosa of Jlanzani, called PoLYODONTE by Ret.n· ieri, and E~molpe maxima by Oken, seems to be closely allied to the AcoETEs; tts proboscis and jaws are the same, and neither of the genera has, perhaps, been described from perfect specimens. Thet·e remain various Ann elides so imperfectly described that ~ve are unable to characterize them well; such are the Nereis cwca, Fabr., Soc. lhst. N_at.'.~0P1~"· part I, pl. iv, f. 24-28;-.N. ~onga, Jd., lb., f. 11-13;-.N. .aphr~dtl~l X~l ;', 4-7. lb 11-13·-Branchianus quadrangulatus, Montag., Lm. Ttans' 'P xiv 'f . 5·.-,D i'YI[otes' hyalina, Id., Ib., f. 6 and 7; and t h e pre t encl ed Hiru.d o db rtahn · ' ' -r 1 · · f " l 1 ve also om1tte e C1,;ata Arcbib Menzies, Lin. Trans. I, p · xvu, · ..,. la 1 . M'••Y nU'. NlB and ·t wo or three other genera of M. Sav1· gny, on accoun t of my Javmg had no opportunity to re-examine thefl_l· in the An· (4) It will be more minutely descr1bed by Messrs Aud., and Cuv., nales des Sciences Naturelles. ABRANCHIATiE. 463 ORDER ·In. ABRANCHIAT .JE. The Abranchiatre have no apparent external organ of respiration whatever, and appear to respire, some, like the Lumbrici, by the entire surface of the skin, and others, like the Hitudines, by internal cavities. They have a closed circulating system, usually filled with red blood, and, like all the Annelides, a knotted nervous cord( I). Some are also provided with setre which enable them to crawl, and others are deprived of them. This has caused their division into two families. FAMILY I. ABRANCHIAT .lE SETIGER.E. This first family compris~s the Lumbrici and Naides of Linn:eus. LuMBRicus, Lin. The Earth-worms, as they are commonly called, characterized by a long, cylindrical body, divided by rugre into a great number of rings, and by an edentated mouth, necessarily required to be subdivided. LUMBRicus, Cuv. Eyes, tentacula, branchire and cirri, all wanting; a tubercle or visible enlargement, particularly sensible in the nuptial season, serves to attach the two sexes to each other in coitu. The intestine is straight and rugose, and in the anterior part of the body we observe some whitish glands which appear to be concerned in the process of generation. The Lumbrici are certainly hermaphrodites, but it is possible that their coalescing may serve to excite them to the act of (1) For the anatomy and physiology of the abranchiate Annelides see the Memoir of M. .!lnt. Dugea, Annales des Sciences Naturelles, Sept. 1828. |