More Clasp Knives.

Unfortunately there is no date on this one, but it appears to be a lock knife.

Blade markings: WHITBY  MADE IN ITALY.

http://www.blog.antiquesnavigator.com/price-guide/antique-knives_hq/54/1.html;

 Two seaman's clasp knives with integral suspension rings and marlin spike. Marked 18th century, but I would guess early to mid 18th century.  

Another suspension ring clasp knife marked 18th century. This one has a wood handle.

http://www.blog.antiquesnavigator.com/price-guide/antique-knives_hq/54/1.html;

This one is of unknown origin. All metal. My guess would be another seaman's knife looking at the fish tail. Also of course a suspension ring type.

http://www.vikingsword.com/vb/showthread.php?t=15074;