      
|
|||||||||||||
|
 |
||||||||||||
 |
 |
||||||||||||
| Central pecten (cp) of 18 to 24 narrow teeth with nearly parallel sides and sharp tips; often abutting each other. An uncommon variation exists where the central pecten consists of 7-14 close set ovately tapered teeth. | Central pecten (cp) of 2 to 8 stout teeth; usually separated from each other and from adjacent pectens by a space. |
||||||||||||
| Taxonomy | |||||||||||||
|
|||||||||||||