304 MARINE INVERTEBRATES 



Porcelanous i Resembling porcelain. 



Bad'tila : Same as lingual ribbon. 



Reticulated : Having distinct lines or veins crossing like a net- 

 work ; covered with netted lines. 



Sculpture : Elevated or impressed marks on the surface ; mark- 

 ings resulting from irregularity of surface ; tracery. 



Sinistral : Having the aperture of the shell at the left ; opposite 

 of dextral. 



Sinuate : Curved in and out ; wavy. 



Siphon: A tubular fold, or prolongation of the mantle forming 

 a tube. 



Spire: All the whorls of a spiral univalve, above the first 

 large body- whorl. 



Suture : The line of junction of the successive whorls of a uni- 

 valve shell, or the line of closure of the opposite valves of a 

 bivalve shell. 



Teeth : Tooth-like projections on the hinge of a bivalve shell. 



Testaceous : Having a hard shell, as distinguished from crusta- 

 ceous, or soft-shelled. 



Turbinate : Shaped like a whipping-top ; whorled from a broad 

 base to an apex. 



Umbilicus : A central, navel-like depression in the body- whorl ; 

 a circular, more or less central pit or hollow. 



Umbo: The beak of a bivalve shell; the protuberance of each 

 valve above the hinge. 



Varices, plural of Varix : Raised marks on the shell denoting 

 a former position of the lip of the aperture, and indicating periods 

 of rest. 



Varicose: Having prominent and tortuous formations on the 

 shell. 



Ventricose: Having the whorls of the shell swollen or strongly 

 convex. 



IVhorl: One of the turns of a spiral shell. Body-whorl, the 

 last whorl. 



