GLOSSARY, 
Pelythalmous, divided into several | 
chambers. 
Prismatic, generally applied to the 
colours of shells being like those 
of the prism ; iridescent, 
Froduced, lengthened out. 
Protrude, to thrust forward, 
Protuberances, plaits higher or more 
elevated than the parts adjoining. 
Punctated, with small hollows like 
the punctures of a thimble. 
Pyramidal, inthe form of a pyramid. 
Pyriform, pear-shaped. 
Q 
Quadrangular, having four right 
_ angles. 
Quadriplicated, having four plaits. 
R 
Radiated, furnished with rays. 
Radicated, is when the shell is fixed 
Reflened, ¢ the same as vecurvated. 
Refracted, 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, formed like a piece of 
net work. 
Retroflected, hent backwards. 
Retrousse, cocked up, turned up. 
Retroverted, turned back. 
Retuse, ending in an obtuse sinus. 
Retundated, blunted, or turned at 
the edge. 
Reversed spire, is when the volu- 
_ tions turn the reverse way of a 
common cork-screw, or to the 
sun’s apparent motion. 
Revolute, rolled backwards. 
Rhomboidal, having a rhombic, or 
four-sided form. 
Ribbed, having longitudinal, 
transverse ridges. 
Ridge, the upper part of a slope. 
Rima, the interstice between the 
valves when the hymen is re- 
moved. 
Rostrated, beaked, the receptacle 
for the canal in univalves, and is 
applied to some bivalves where 
one of the sides is prolonged, as in 
Tellina rostrata. 
Rostrum, the beak ; the extension 
or 
131 
of the base of the shell, in which 
' the canal is situated. 
Rotund, round, circular, spherical. 
Rudimentary, the commencement, 
or first elements of any thing; 
generally applied to the indistinct 
teeth of shells. 
Rufous, reddish brown. 
Rugose, rugged, full of wrinkles. 
Ss 
Salient, prominent, jutting out. 
Sanguinaceous, of a blood colour. 
Secabrous, rough, rugged, or like a 
fil 
e. 
Scalloped, indented at the edges. 
Scrobiculate, pitted, having the 
surface covered with hollows. 
Serobicotous, a depression or cavity. 
Scutellated, : 
Scutellitorta, ¢ shield-shaped. 
Seam, the line formed by the union 
of the valves. 
Securiform, hatchet-shaped.” - 
Semi, is used in composition in the 
sense of half. 
Semi-cordate, half heart-shaped. 
Semi-cylindrical, half cylindrical, 
cut through length-ways. 
page ree gee the shape of a half 
obe. 
Sera sennes the shape ofa half moon. 
Semi-pellucid, somewhat pellucid, 
or shining. 
Septiform, in the shape of a parti- 
tion. 
Serrated, like the teeth of a saw. 
Serrulated, very minutely serrated. 
Sessile, sitting or seated. 
Seta, a bristle. 
Setaceous, bristly, covered with 
bristles. 
Setiferous, bearing bristles, hairy. 
Setose, covered with bristles. 
Sinister valve, is the left valve. 
Sinus, a groove or cavity. 
Siphon, a pipe or tube; as in the 
genera Ammonites, Nautilus, and 
Endosiphonites, &c. 
Siphuncle, a cylindrical canal per- 
forating the partitions in poly- 
thalamous shells ; asin the Spirula 
Peroniti, Ammonites, Nautilus, &c. 
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 
genus, containing such as agree 
with it in general characteristics, 
but disagreeing in particular parts; 
or such as are derived from one 
common parentage. 
