GLOSSARY. 



227 



Tetragonal, four cornered. 



Torose, swelling into knobs or pro- 

 tuberances. 



Tortuosity, -oTeath, flexure. 



Tortuous, twisted, wreathed, wind- 

 ing. 



Transverse, placed across, or cross- 

 ways. When the breadth of a 

 she'll is greater than its length, 

 it is called transverse. 



Trapeziform, shaped like a tra- 

 pezium. 



Trigonal, having three angles. 



Truncated, stunted, cut short or 

 abruptly off at the end. 



Tubercle, a little knot or pimple. 



Tuberculated, knotted, pimpled. 



Tuberosities, proniinent knots or 

 excrescences. 



Tubicolar, inhabiting a tube. 



Tubular, in the shape of a hollow 

 tube. 



Tubulate, tubulous or hoUow. 



Tunicated, coated. 



Turbinated, shaped like a top or 

 pear. 



Turgid, swollen. 



U & V. 



Valve, a distinct piece or part : the 

 whole of univalve shells, or shells 

 in one piece ; and the half of bi- 

 valves, or shells in two divisions, 

 &c. 



Varices, longitudinal thick ribs in 

 univalve shells. 



Variety, is when one species differs 

 some little degree from that of 

 another. 



Vaulted, arched, like the roof of 

 one's mouth. 



Venter, the belly, situated in the 

 body of the shell ; being the most 

 prominent part, when the aper- 

 ture is turned to the observer. 



Ventral, belonging to the beUy. 



Ventricose, inflated, swollen in the 



middle. 

 Vermiform, vporm-shaped. 

 Vertex, in the Patella the top or 



most prominent part, situated in 



general nearly in the middle. In 



the genus Bulla it is used for the 



apex. 

 Verrucose, warty. 

 Verticillate, whorled. 

 Umbilicated, having a depression 



in the centre like a navel. 

 Umbo, in bivalve shells, the promi- 

 nent part which tui-us over the 



hinge. 

 Umbonate, bossed, having a raised 



knob in the centre. 

 Undulated, waved, having a waved 



surface. 

 Ungvdate, shaped Kke a horse's 



hoof 

 Unilocular, with a single chamber 



or compartment. 

 Univalve, shells consisting of one 



valve, or piece. 

 Volutions, the wreaths, or turnings 



of the shells of univalves. 

 Urceolate, swelling in the middle 



like a pitcher. 

 Vulva, a mark in several bivalve 



shells ; formed when the valves 



are united on the posterior and 



anterior slopes. 



W. 



Whorl, one of the wreaths or turn- 

 ings of the spire of univalves. 



Zigzag, having contrary turnings 



and windings. 

 Zoned, surrounded with one or 



more girdles. 



