I would say these pieces date circa 1865, they share certain similarities with Gotham's "Calla Lily" pattern and also the "3-leaf" design on your pieces is similar to the "3-leaf" design on Gorham's "Bird's Nest" pattern, both of which were patented in 1865 ::: There was a designer named George Wilkinson at Gorham during this time and he designed patterns similar to this, so perhaps he was the designer or at least he greatly influenced the design elements here :::
I don't know if your pieces have a pattern name, but collectors might refer to them as "ball-end" or something like that ::: There was an "aesthetic movement" in silver during this time and many of the pieces had naturalistic elements (such as leaves) or geometric elements (such as spheres), and in your case we have a combination of these two elements ::: This piece seems to fall into the category of "aesthetic movement silver" and many collectors would describe your pieces as such :::
I think your knife might be a fish knife, and your fork might be a seafood fork, I have a feeling that this was part of an ornate fish set, but I could be wrong there ::: Maybe the knife is a butter knife and the fork is an olive fork? :::
This is the only similar piece I could find, but it might not be an exact match :::

