. The illustrated natural history [microform]. Reptiles; Fishes; Mollusks; Natural history; Reptiles; Poissons; Mollusques; Sciences naturelles. INDIAN VnORVS.—rkoriis 'liuliais. STAIIICASE on PHIlsrKCTl vr, TUOl'(.Wn«»i funrecanim. not very particular about this drawback, neither is the thrusli, wliich, in winter, wlien the snails arc liidilcn awiiy in their chirk recesses, liuJs ii meal easier to bo obtained on the sea-shore than in hunting I'or its usual lirey. Onk of tlio prettiest members of this family is the WlNDIXd Staiucase-SHELL, or I'i'.Rsi'KC'TivE Tkocuus, SO named on accoun
. The illustrated natural history [microform]. Reptiles; Fishes; Mollusks; Natural history; Reptiles; Poissons; Mollusques; Sciences naturelles. INDIAN VnORVS.—rkoriis 'liuliais. STAIIICASE on PHIlsrKCTl vr, TUOl'(.Wn«»i funrecanim. not very particular about this drawback, neither is the thrusli, wliich, in winter, wlien the snails arc liidilcn awiiy in their chirk recesses, liuJs ii meal easier to bo obtained on the sea-shore than in hunting I'or its usual lirey. Onk of tlio prettiest members of this family is the WlNDIXd Staiucase-SHELL, or I'i'.Rsi'KC'TivE Tkocuus, SO named on account of the peculiar formation of its whorls. If tlie sliell be held witli its to]) downwards, it looks exactly as if it had been wound around a conical centre which had aft(;r,vards been witlidrawn, and the projecting I'llj^es of the wliorls have a wonderful resemblance to the perspective view of a winding staircase seen from bidow. lVrlia])S the most remarkable point about this genus is the singular operculum of some of the s|H'cies, whieli dilVers from that of any othei' mollusc. Instead of being a nearly lliit plate of horny or shelly sul)stance, it is a conical structure of shelly matter with a riliand of mend)ranous substance wound round it, and iiroj'ecting like the mechanical foini so well known as Archimedes' screw. The object of this singular variation is (initc uiiknown. The colour of the shell is rather variable, but consists of mottlings with brown, ochre, and white. A VEKV curious member of this family is the LooriNc^ Snail {Truncatella truncdtula), a little s[)ecies that is remarkable for the habit which has earned for it its popular name. All these creatures inhabit the space between tide marks, and can live for many weeks without water. Tluiir mode of i)rogression is very ])eculiar, and closely resendiles that of the leeches or looping geometric caterpillars with which we are .so familiar. When they ,>':.VV,. Please note that these images are extracted from
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Keywords: ., bookcentury1800, booksubj, booksubjectfishes, booksubjectmollusks
