THE POLYPUS. 



567 



which thousands of minute species of insects 

 remain to this very day. It is true, indeed, 

 that Reaumur observed, classed, and named 

 them. By contemplating their motions, he 

 was enabled distinctly to pronounce on their 

 being of the animal and not of the vegetable 

 kingdom ; and he called them polypi, from 

 their great resemblance to those larger ones 

 that were found in the ocean. Still, however, 

 their properties were neglected, and their his- 

 tory unknown. 



Mr Trembley was the person to whom we 

 owe the first discovery of the amazing proper- 

 ties and powers of this little vivacious crea- 

 ture. He divided this class of animals into 

 four different kinds : into those inclining to 

 green, those of a brownish cast, those of a 

 flesh colour, and those whichhe calls \\\zpolype 

 de panache. The differences of structure in 

 these, as also of colour, are observable enough ; 

 but the manner of their subsisting, of seiz- 



polypiferous mass. Fig. 62 represents the tentacula in 

 the polypes of this species. Fig. 63 is a portion of one 

 of these tentacula highly magnified. Fig. 64 is a de- 

 lineation of one of the gemmules, greatly magnified. 

 Fig. 78 is a part of F. verticiliata greatly magnified. 



SECTION VI. 



Polypiferous masses consisting of one substance only, 

 slender, fistulous, membranous, or homy stems, flexible 

 and branched, containing polypi in their interior. Poly- 

 fthysu; polypiferous mass fungoid, with a calcareous 

 crust. Aoctabulum ; fungoid, with a calcareous crust. 

 Tibiana ; adherent, tubular, membranaceous, or horny. 

 Dichotomariafruticulosa., pi. 30, f. 43. Polypiferous mass 

 with tubular, subarticulate, dichotomous stems, and a 

 calcareous incrustation. American seas. Fig. 44 repre- 

 sents the D. obtusata, an inhabitant of the coasts of the 

 Bahama islands. An</uinaria spatulata, pi. 30, f. 45. 

 Adherent, and extending itself in the form of a plant. 

 Fig. 46 is a magnified portion. Cellaria thuia, pi. 30, f. 

 47. Adherent, with the stems tubular and branched. 

 Fig. 48, a portion of a stem magnified. European seas, 

 Liriozou Caribcea, pi. 30, f. 49. Adherent, branched, 

 calcareous ; with tubular stems, jointed, creeping. Fig. 

 50, a portion of a stem magnified. West Indian seas. 

 Scrinlaria lendigera, pi. 30, f. 51. Adherent, branched, 

 horny, stems, slender. Fig. 52, a portion of a stem 

 magnified. European seas. Plumularia myriophi/lujii, 

 pi. 30, f. 53. Adherent, branched, horny, stalks slender. 

 Fig. 54, a portion of a stem magnified. European seas. 

 Antennularia ramosa, pi. 30, f. 55. Adherent, horny, 

 with the stems fistulous, simple, or branched, Fig. 56, 

 a portion of a stem magnified. European seas. Sertu- 

 (aria frutescens, pi. 30, f. 10. Adherent, horny, steins 

 slender and fistulous. Fig. 4, a portion of a stem mag- 

 nified. European seas. S. abietina, pi. 30, f. 73 and 77. 

 Campamdlaria verticiliata, pi. 30, f. 57. Adherent, stems 

 fistulous, filiform, horny, simple, or branched. Fig. 58, 

 a magnified portion of a branch. Cornularia; adherent, 

 horny, with simple, funnel-shaped stems. Tubularia 

 ramosa, pi. 30, f. 59. Adherent, slender, tubular, sim- 

 ple, or branched, horny. Fig. GO, a magnified portion 

 of a branch. British seas. Fig. 74, T. magnifica. Tro- 

 pical seas. Plumatella; adherent, slender, tubular, 

 branching, submembranous, extremities of stems and 

 branches terminated each by a polypus. 



SECTION VII. 



Polypi ferous masses either free, isolated, and floating 

 in the water, or adherent, and agglomerated in cellular 

 masses, composed of one substance on aquatic bodies; 

 polypi provided with numerous tentacula, which do not 



ing their prey, and of their propagation, is 

 pretty nearly the same in all. 



Whoever has looked with care into the bot- 

 tom of a wet ditch when the water is stag- 

 nant, and the sun has been powerful, may re- 

 member to have seen many little transparent 

 lumps of jelly, about the size of a pea, and 

 flatted on each side ; such also as have exa- 

 mined the under side of the broad-leafed 

 weeds that grow on the surface of the water, 

 must have observed them studded with a num- 

 ber of these little jelly-like substances, which 

 were probably then disregarded, because their 

 nature and history were unknown. These 

 little substances, however, were no other than 

 living polypi, gathered up into a quiescent 

 state, and seemingly inanimate, because either 

 undisturbed, or not excited by the calls of appe- 

 tite to action. When they are seen exerting 

 themselves, they put on a very different appear- 

 ance from that when at rest: to conceive a just 



complete the circle round the mouth. The animals of 

 this section chiefly inhabit fresh water. Alcyonella; in- 

 crusting, thick, convex, and irregular, consisting of an 

 aggregation of vertical subpentangular tubes, open at 

 thftir summit. Spongilla ; adherent polymorphous, cel- 

 lular, irregular, composed of subpiliferous laminas. 

 Cristatella ; free, globular, gelatinous, covered by short, 

 thick, polypiferous tubercles, each of which encloses ?i 

 polypus. Difflugia; body small, gelatinous, contractile, 

 enclosed in a testaceous tube, projecting. 



ORDER IV. POLYPI DENUDATI. 



Polypi provided with tentacula, and not forming apoly- 

 piferous mass; greatly diversified in form, in the num- 

 ber and situation of their tentacula, and fixed either 

 constantly or spontaneously. Pedicellaria; adherent, 

 formed of a stiff peduncle. Coryne ; fleshy, seated on a 

 peduncle. Hydra viridis, pi. 30, f. 76. Oblong, linear, 

 in the form of a reversed cone, narrowed below, gelatin- 

 ous, transparent, and fixed spontaneously by the base, 

 a. exhibits the body extended, and b. the body in a 

 contracted state. Fig. 69, body expanded. Inhabits 

 fresh waters. 



ORDER V. POLYPI CILIATI. 



Mouth provided with ciliated and gyratory organs 

 which agitate the water, but do not seize the food. 



SECTION I. ROTIFERI. 



With one or many organs in a circular form, ciliated, 

 and rotatory at the opening of the mouth. Tztfncolaria ; 

 body contractile, oblong, contained in a tube fixed on 

 aquatic bodies. Vorticella polypina, pi. 30, f. 75. 

 Body naked, pedunculated, fixed spontaneously, or con- 

 stantly by its base. Inhabits stagnant waters. Urceo- 

 laria ; body free, contractile, urceolate, sometimes elon- 

 gated, without tail or peduncle. Furcularia; body free, 

 contractile, oblong, provided with a short or elongated 

 tail. Bracliionus ; body free, contractile, nearly oval, 

 covered, at least partly, by a transparent sheath. Fol- 

 liculina; body contractile, oblong, inclosed in a trans- 

 parent sheath. 



SECTION II. VIBRATILES. 



Cilise placed near the mouth, moving in interrupted 

 vibrations. Vaginicola; body minute, oval, or oblong, 

 anteriorly ciliated, and provided with a tail; enclosed in 

 a transverse sheath, but not attached. Tridiocerca; 

 body minute, oval, or oblong, anteriorly truncated. 

 Rattulus; body minute, oblong, truncated, or anteriorly 

 obtuse. 



