Below are some photographs of Yorkshire slugs. Limax cinereoniger is a local slug which can be variable in colour and does not like disturbance. This is a specimen from near Pately Bridge.
Below is a specimen of Malacolimax tennelus also from near Pately Bridge. This is an extremely local and uncommon slug usually found from late September to early November.
Below is another specimen of Limax cinereoniger this time from near Kettlewell