175 



Pdlythalmous, divided into several 

 chambers. 



Porcate, marked with raised longi- 

 tudinal lines. 



Porrected, 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. 



Radiated, furnished with ravs. 

 Radicated, is when the shell is fixed 



by the base to another body. 

 Rectangular, having right angles, 

 r.ecurvated, turned backwards. 

 Recurved, bowed back. 

 Reflected, thrown backwards, or bent 



back. 



Reflex' d j^hesameas recurvated. 



Retracted, abruptly bent, as if broken. 



Reniform, kidney-shaped. 



Repand. with a serpentine margin. 



Replicated, folded or plaited, so as to 

 form a groove or channel. 



Reticulated, f.)rraed like a piece of net 

 work. 



Retroflected, bent backwards. 



Retrousse, cocked up, turned tip. 



Retroverted, turned back. 



Rt^tuse, ending in an obtuse sinus. 



Retundated, blunted, or turned at the 

 edge. 



Reversed spire, is when the 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. 



Rima, 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, the commencement, or 

 first elements of any thing; generally 

 applied to the indistinct teeth of 

 shells. 



Rufous, of a reddish colour. 



Rugose, rugged, full of wrinkles. 



S. 



Sanguinaceous, of a blood colour, or 

 resembling blood. 



Scabrous, rough, rwgged, harsh, or 

 like a file. 



Scalloped, indented at the edges. 



Scorbiculate, pitted, having the sur- 

 face covered with hollows. 



Scorbiculous, a depression or cavity 



Scutellated, >^i- .^^i . 



Scutelliform,r^"*'''^'^^''P''''' 



Seam, the line formed by the union 

 of the valves. 



Semi, is used in composition in the 

 sense of half. 



Serai-cordate, half hpart-shaped. 



Serai.cylindrical, half cylindrical, cut 

 throusf h lengthways. 



Semi.orbicular, the shape of a half 

 globe. 



Semi-lunar, the shape of a half moon. 



Semi-pellucid, somewhat pellucid, or 

 shining. 



Septiform, in the shape of a partition. 



Serrated, like the teeth of a saw. 



Serrulated, very minutely serrated. 



Sessile, sitting or seated. 



Seta, a bristle. 



Setaceous, bristlv, coA'ered with bris- 

 tles. 



Setiferous, bearing bristles. 



Setose, Covered with bristles. 



Sinister valve, is the left valve- 

 Sinus, a groove or cavity. 



Siphunculus, a cylindrical canal per, 

 forating the partitions in polythala- 

 mous shells; for instance, as in the 

 Nautilus Spii-ula, 



Solitary, generally applied to a single 

 tooth in bivalves. 



Spatulate, rounded and broad at the 

 top, and becoming narrow like a 

 spatula or battledore. 



Specie.s, the division of a family or gen. 

 us, containing such 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- 

 liog. 



Spire, all the Avhorls of univalve shells, 

 excepting the one in which tlie 

 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. 



