Sorry but unless you provide details no one can help
What software do you have? You state OS X 10.10.1 - if that is correct then you have iPhoto and if has no ability to use iCloud Photo Library.
How exactly did you "store your photos in iCloud"?
The " is an indication that the connection between the thumbnail and the photos has been broken
- this can be due to library corruption - a rebuild will usually fix that - backup your iPhoto library and launch iPhoto while holding down the option and command keys, repair permissions and then rebuild your database
OR
User actions mucking around in the iphoto library or using clean up software (HINT - Do not use ANY cleanup software on your Mac) - the only solution to user action is to restore your backup form before you tok actions that damaged your library
LN