IT* 



PALM V HA. 



PAI.MVRA. [BOUMC&J 



PALXYItA, gnus of DoraibraiMhkte AumetU*. 



PALO DKVACA. fCow-Tajsi.] 



PALI'EBRA. [Kit.] 



PALUDINID.K, family of Proeobranohiate Oasteropodous Mol- 

 i*M. TtM species are all inhabitant* of the fresh water. They 

 stain am Lamarck's family of Periatomiana. The genera included in 

 Ik art PttmduM, Valnna, Ampulloria, Ampkibolo, and BilMinio. 

 Through Ampmltarui the family it allied with tferitido. The animal* 

 ban broad muuie-abaped bead*, produced teotacula, sessile or sub- 

 MMtle eyes, and round or orate entire-mouthed turliinated shells. 

 They are distributed all over the world, in lake* and streams. All 

 UM species are operculated. Some of the Polmdituf are amongst tbe 

 "a, whilst othen are the smallest They are 

 are brilliantly coloured. Their foaail forma 

 > titoM which are recent, and they are found 

 a* far back at* UM Oolitic period. 



PWwb'M (Lam.). Animal furnished with a proboecidiform head ; 

 mouth toolbUu, but containing a small lingual l.rintly mags ; tentacles 

 conic, tonga tod, contractile ; eyes at the external base of the ten- 

 Ucl ; foot oral, with a marginal furrow at iu anterior part ; male 

 organ rery large, swelling up the right tentacle, whence it comes forth 

 from an orifice situated near iU base; anus at the extremity of a 

 small tube in UM flooring (plancher) of the respiratory cavity. 



8bll furnished with an epidermis, conoid, having the whorls of the 

 spire rounded, and the apex mam initiated ; aperture rounded, oval, 

 angular at the summit, the borders united and trenchant. 



Operculnm horny, its elements concentric, with its summit exoentric. 



ins sinus* sni imsunmuKi 

 largest freab-water shells, 

 mosOy dingy ; but some i 

 do not greatly differ from 



fmlnJim pamla. Animal and thell magnified. 

 *, tide Tlew; , seen from above. (Uuildlng.) 



Lamarck states that the f'almdinir, many species of which have been 

 confounded with the CycbHomata, Sulint, and Turbine*, inhabit 

 fresh-waters almost generally, but some live also in brackish and even 

 in quite Mlt-waton. They breathe water only, like the Volvota, with 

 which they have a great affinity ; but their branchiaj are internal, and 

 they are further distinguished from that genus by the form of their 

 aperture, which is rather longer than it is wide, being modified by the 

 last whorl, which present* an angle at its summit. Their habits he 

 describe, as being very.nearly those of the Lymnra, like which the 

 Ptlmdina may be often seen progressing at the surface of the water, 

 foot uppermost. 



This form is widely spread. Specie* have been found in Europe, 

 Asia, Africa, and America. The European specie* are the inhabitant* 

 of temperate climate*. 



Tbe number of recent specie* of Pattutina given by Woodward is 

 60 and of fossil species SO. 



f. rintMro, UM Common River-Snail, has the shell ventrioose-conoid, 

 UUn, diaphanous, very delicately striated longitudinally, greenish 

 brown, with brown-red obsolete transverse bands; five turgidly 

 rounded whorls, tbe sutures strongly marked. It inhabits the fresh- 

 waters, rivers, and pond* of England, France, Germany, Ac. 



/WWiKu ririfor*. Female. 

 aa ataK, with young shells In It j , operculum ; t, young the! 



Swainson, and liiikini.i, Gray, are sub-genera of Paludina 

 HanUy record two specie* of Hiikitua as British, B. ten 



, 



tacula; two great subulate tentacula nearly as long as the foot, 

 supporting at their baho oculiferoiis peduncles, aometimes separated 

 throughout their length. No jaws, but a lingual bristled ribbon. A 

 respiratory canal formed by the mantle, but not leaving any trace ou 

 the shell. Branchial cavity of great size, largely open anteriorly, and 

 whose upper wall is doubled so as to form a great aquiferous sac. 

 Deshayes, principally.) 



Shell furnished with an epidermis, generally not stout, but globular, 

 ventrioose, and umbilicated ; spire very short, the last whorl much 

 arger than all the others put together ; aperture oval, rather longer 

 than it is wide, borders united, the right lip trenchant. 



Operculum horny or shelly, rarely calcareous, rather delicate, 

 composed of concentric elements, the apex subuiarginal and inferior. 



. 



U-Mi(LMarckV Animal globular or planorbiform ; foot 

 lattoned terminated anteriorly by a pair of conical buccal ten 



Amfultaria Juliia. Animal in the shell creeping. (Gulldlng.) 

 n, operculum ; 6, the right ij hon ; r, the left lijihon. 



Ampultaria dutia, showing the lower Bide of the foot, &c. (Ouilding.) The 

 animal I* represented an ucendlng to the mirfacc of. the wsU-r to breathe, and 

 with the respiratory tiphon cxscrted. a, the operculum ; , the right aiphon ; 

 r, the left siphon. 



The species of this genus are not found in Europe, but they have 

 been brought to Europe alive. The first was sent to ParU by 

 M. Caillaud from the Nile. Thiit naturalist, during his voyage to 

 Meroe, collected several Egyptian Molttuca, which he distributed 

 generously among collectors. One correspondent had been anxious 

 for the fluviatile molluscs found in the Nile. The person employed 

 to collect these, after having gathered a large quantity of river Mottutca, 

 among which were some living A mpvllarirr, put them all into a box 

 of bran (son). This box was . its road by the operation of 



the quarantine laws for four months, and when it reached M. Caillaud, 

 was in such a state, from the putrefaction of the greater part of its 

 animal contents, that he hastened to throw the whole into the water. 

 To hii no small surprise he found, a few hours after, the greater part 

 of the AmpvJlana, which had been shut up with this mass of putre- 



