16 CATECHISM OF CONCHOLOGY. 



by means of which some species of the genus 

 Anomia adhere to different substances. 



Q. What is the meaning of Labium ? 



A. It signifies in Univalves, the sides of the 

 aperture; in Bivalves, the exterior edge of the 

 valves. 



Q. What is the Tinus? 



A. A deep cut, as in the lip of the Nuren 

 Babylonicus. 



Q. I do not understand the meaning of the 

 term Ligament. 



A. It signifies a cartilage which closes the 

 suture fixed between the internal and external 

 lips of the shell, and connects the valves. 



Q. Pray what does the word Limbus signify ? 



A. Circumference within the margin. 



Q. What does Lunula, or Lunule mean ? 



A. A small crescent-shaped depression, on 

 either side of the area or areolo. 



Q. What are the Radii, or Rays ? 



A. Elevated strioe or lines tending from the 

 centre of the shell to the periphery, or circum- 

 ference. 



Q, What is the Rima or Suture? 



