306 



EAST COAST MAEIHE SHELLS 



Radiating lines.... In bivalves, lines extending 



from umbones outward; opposed to concentric 



lines 

 Radula. .. .Lingual ribbon, p. 18 

 Recurved. .. .Bowed downward 

 Reference books.... p. 8 

 Reflexed. . . .Bent backward 

 Renlform. . . .Kidney-shaped 

 Reproduction. .. .p. 17 

 Reslllum. . . .An Internal ligament in bivalves, 



p. 17 

 Reticulate. .. .Resembling a network 

 Retuse. .. .Ending In an obtuse summit 

 Right valve.... p. 15 

 Rlmate. . . .Form of umbilicus, p. 13 

 Rostrate. .. .Pointed or beaked at end, usually 



the anterior end of bivalves 

 Rufous. .. .Red or pale red 

 Rugose. .. .Wrinkled or creased 



Scalariform. .. .Whorls separated from one another 

 as in Epitonium 



Scalloped. .. .Indented on edge 



Scaphopoda. . . .A class, pp. 1, 71 



Sculpture,.. .pp. 12, 17 



Septate. .. .Interior of aperture contracted by 

 projecting shelly masses 



Septum. . . .Diaphragm 



Serrate. .. .Like teeth of a saw 



Sinistral Left-handed, p. 11 



Sinuous. . . .Twisted 



Sinus Excavation, as if scooped out; indenta- 

 tion 



Siphons. .. .Tubes of bivalve animal used for im- 

 bibing clean water or discharging wastes 



Spinose Armed with sharp spines; see muricate 



Spiral. .. .Wound around an imaginary axis 



Spiral operculum. .. .p. 14 



Spirally striated Sculpture following direc- 

 tion of growth 



Spire That portion of a univalve shell exclu- 

 sive of the last whorl, p. 13 



Stenoglossa. . . .p. 114 



Striated. .. .With parallel impressions or raised 

 lines; with thread-like lines 



Strigose. .. .Covered with short bristles; lean, 

 thin 



Sulcate Heaviest at the base; furrowed with 



wide grooves or channels as in Trivia, PI. 40, 

 Fig. 7 



Subulate Awl-shaped 



Suture. .. .Line of separation between whorls, p. 14 



Symmetrical Univalves with two equal sides 



and the nucleus central 



Taxonomy. .. .The study of the laws of classifica- 

 tion 



Teeth.... In bivalves an arrangement of eminences 

 and depressions on edges, used for locking the 

 valves. In the center are the cardinal, at 

 the sides the lateral teeth 

 In univalves found adjacent to and partially 

 closing the aperture 



Translucent. .. .Transmitting light 



Transverse aperture. .. .At right angles with axis 

 of shell 



Trapezoidal. .. .Shell quadrilateral in outline 

 and opposite sides, although more or less 

 straight, not parallel 



Trlnomialism. . . .p. 11 



Trochlform. . . .Of conical shape but flattened be- 

 low as in Astraea, PI. 31, Fig. 2 



Trochophore. .. .Development of egg stage, p. 1 



Truncate. .. .Cut off at tip 



Tubercles. .. .Small projections 



Tumid. .. .Swollen, applied to bivalves 



Turbinate. .. .Top-shaped or conical and rounded 

 below as in Turbo; PI. 31, Fig. 11 



Turreted — .Elongate, with upper whorls angulat- 

 ed or shouldered as in Turritella, PI. 37, 

 Fig. 15 



Umbilicus. .. .A chink or pit at axis of the spi- 

 ral revolution, varying greatly in different 

 species; often absent or indistinct, p. 13 



Umbo.... The beginning of a bivalve shell, which 

 usually emerged from the egg, often elevated 

 and nearly always pointing forward, p. 16 



Oncinal teeth. .. .Portion of radula, p. 18 



Undulated. . . .Waved 



Unguiculate operculum. .. .p. 14 



Univalve. .. .Single valve or part 



Varices. .. .Prominent raised ribs on surface of 

 univalve shells, corresponding to rest peri- 

 ods and periodic thickenings of the lip 



Varicose. .. .See varices 



Varix....A single one of the varices. Fig. lie, 

 p. 14 



Veliger larva. .. .Development of the egg stage, 

 p. 1 



Ventricose. . . .Swollen 



Viscid. .. .Covered with resinous or greasy matter 



Viviparous. .. .Producing living young 



Whorl.... One complete revolution of the spiral 



shell 



