175 



Polytbalmous, divided into several 



clwinbers. 

 Porcate, marked with raised lontji- 



tudinal lines. 

 pKirected, projecting. 

 Prismatic, generally applied to the 



colours of shells, being like those of 



the prism ; iridescent. 

 Produced, lengthened out. 

 Protrude, to thrust forward. 

 Protuberances, plaits higher or more 



elevated than the parts adjoining. 

 Punctuated, with small hollows like 



the punctures of a thimble. 

 Pyriform, pear-shaped. 



Quadrangular, having four right an- 

 gles. 

 Quadriplicated, having four plaits. 



R. 



Radiated, furnished with rays. 

 Radicated, is when the shell is fixed 



by the base to another body. 

 Rt^ctangular, having right angles. 

 Eecurvated, turned backwards. 

 Recurved, bowed back. 

 Reflected, thrown backwards, or bent 



back. 



Reliexed, }^''*^ ^^™'^ ^^ recurvated. 



Refracted, abruptly bent, as if broken. 



Reiiiform, kidney-sliaped. 



Repand. with a serpentine margin. 



Replicated, folded or plaited, so as to 

 form a groove or channel. 



Reticulated, f.)rmed like a piece of net 

 work. 



Retroflected, bent backwards. 



Retrousse, cocked up, turned tip. 



Retroverted, turned back. 



Retuse, ending in an obtuse sinus. 



Retundated, blunted, or turned at the 

 edge. 



Reversed spire, is when tlie volutions 

 turn the reverse way of a common 

 cork screw, or to the sun's apparent 

 motion. 



Revolute, rolled backwards. 



Ribbed, having longitudinal, or trans- 

 verse ridges. 



Ridge, the upper part of a slope. 



Ritna, the interstice between the 

 valves when the hymen is removed. 



Rostrum, the beak ; the extension of 

 the shell, in which the canal is situ- 

 ated. 



Rotund, round, circular, spherical. 



Rudimentary, ihe commencement, or 

 lirst elements of any thing; generally 

 applied to the indistinct teeth of 

 sliells. 



Rnfous, of a reddi-h colour. 



Rugose, rugged, full of wrinkles. 



S. 



Sanguinaceous, of a blood colour, or 

 resembling blood. 



Scabrous, rough, rugged, harsh, or 

 like a tile. 



Scalloped, indented at the edges. 



Scorbiculate, pitted, having the sur- 

 face covered with hollows. 



Scorbiculous, a depression or cavity 



Scutellated, ? „i.- i , , , 



Scutelliforra,r'"^''l-^''«P«'d. 



Seam, the line formed by the union 

 of the valves. 



Semi, is used in composition in the 

 sense of half. 



Semi-cordate, half heart-shaped. 



Serai-cylindrical, half cylindrical, cut 

 throun:h lengthways. 



Semi-orbicular, the shape of a half 

 globe. 



Semi-lunar, the shnpe of a half moon. 



Semi-pellucid, somewhat pellucid, or 

 shining. 



Septiform, in the shape of a partition. 



Serrated, like the teetii of a saw. 



Serrulated, very minutely serrated. 



Sessile, sitting or seated. 



Seta, a bristle. 



Setaceous, bristly, covered with bris- 

 tles. 



Setiferous, bearing bristles. 



Setose, covered vvith bristles. 



Sinister valve, is the left valve- 

 Sinus, a groove or cavity. 



Siphunculus, a cylindrical canal per- 

 forating the partitions in poiytha^a- 

 mous shells; for instance, as in the 

 Nautilus Spirula, 



Solitary, generally applied to a single 

 tooth in bivalves. 



Spatulate, rounded and broad at the 

 top, and becoming narrow like a 

 spatula or battledore. 



Species, the division of a family or gen- 

 us, containing sucii as agree with it 

 in generic characters ; or such as are 

 derived from one common paren- 

 tage. 



Spiny, thorny, covered with thorn- 

 like processes. 



Spinous, having spines like a hedge- 

 hog. 



Spire, all the whorls of univalve shells, 

 excepting the one in which the 

 aperture is situated, which is termed 

 the body. 



Spiral, twisted like a cork screw. 



Squamose, scaly. 



Stellated, starred, consisting of star- 

 like figures. 



Striated, scored, or covered with fine 

 thread-like lines. 



Sub, in composition, means almost, 

 or approaching to ; as sub-globose, 

 somewhat globular. 



Sub-arcuated, somewhat arched. 



