A treatise on malacology; or, Shells and shell fish . g the five prin-cipal forms in this family. The Bulimus hcBmastomus(,6.) is the chief of these, and is an exact counterpart of the Achatina ])erdijc Lam. ofthe opposite circle. It is alarge ventricose shell, with aspire much shorter than thebody-whorl, and of only fourvolutions. In the next type,Bulimus interruptus* of La-marck, these proportions arenot preserved; the form ismore slender, the body-whorlless ventricose, the spire morelengthened, and the whole aspectreminds us of Achatina regi-na t and its allies. These are followed by s
A treatise on malacology; or, Shells and shell fish . g the five prin-cipal forms in this family. The Bulimus hcBmastomus(,6.) is the chief of these, and is an exact counterpart of the Achatina ])erdijc Lam. ofthe opposite circle. It is alarge ventricose shell, with aspire much shorter than thebody-whorl, and of only fourvolutions. In the next type,Bulimus interruptus* of La-marck, these proportions arenot preserved; the form ismore slender, the body-whorlless ventricose, the spire morelengthened, and the whole aspectreminds us of Achatina regi-na t and its allies. These are followed by such shells asBui. /M7>; Lam., having very much the cylindrical formof Pupa; the outer lip is nearly round, but there is noinner lip, or any tooth in the pillar. In the third mo-dification we see a complete prototype of the sub-genusGoniostoma, in that singular shell the Bulimus Lyonc-tianus, where the aperture protrudes on one side, andappears distorted. Last of all comes those small Pa-cific species (mistakingly separated as a genus, under. Chemnitz, pi. 101. fig. 938, 939. + Zool. 111. 1st Series. CHAP. VI. TYPES OP THE SUB-GENUS BULIMUS. 179 the name of Partula), where the margin of the aperture^instead of being completely reflected^ as in all the othertypes, is only very much dilated or spread out. Thispeculiar character brings us, of course, to the confinesof the sub-genus Bulimulus; and by such shells as theBulimus melanostomus of Brazil (which will completelyanswer to the characters given of Partula*) we returnagain to B. hcemastomus. By arranging these speciesin a column, as sectional divisions, they will be foundto represent the primary types of the spiral land shellsin the following manner: — Analogies of the Sectional Types of the Sub-genus Bu-limus. Genera of theAchat ince. Bulimus, ACHATINA. SectionalTypes or Species. AnalogicalCharacters. Sub-generaof theBulimi. f Shell vontricose;^I spire short ; )Hamastomus. typical species ][_ always rosy.
Size: 1406px × 1778px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1840, booksubjectmollusks, bookyear184
