Are new directory pages crawled?

[astoller]

I have an index page leading to a directory page of 11 links to internal pages
I updated the directory page 17 Jan and kept index page unchanged

Will Google crawl this new directory and all the links in it as it successfully crawled its predecessor
Or
Will I now lose any listings for these 11 internal pages and be virtually starting from scratch?

My rankings disappeared and I dont know if its the new algo or my new directory page