There are so many elements to correct identification without better pictures or seeing the animal in person it is very difficult. Many people pick up little tips like smoothes having an orange stripe on their bellies and palmates having a tiny filament at the end of the tail, but some of these features are only found in adults, only in either males or females and at the correct time of year.
So if you are going to take a picture of any animal for identification take a picture from every angle and close up shots as well
I would advise this book …
Britain's Reptiles and Amphibians by Howard Inns
Britain's Reptiles and Amphibians