Dusky Slug - Arion subfuscus possible

Dusky Slug - Arion subfuscus possible

Observation - Dusky Slug - Arion subfuscus possible. Description: A small herd of these slugs was inhabiting a broad leaved dock this morning in the rain. I tried touching the mucus and couldn't manage to persuade myself if it was reddish or not, maybe because of the rain. They have dark lateral stripes and central stri

A small herd of these slugs was inhabiting a broad leaved dock this morning in the rain. I tried touching the mucus and couldn't manage to persuade myself if it was reddish or not, maybe because of the rain. They have dark lateral stripes and central stripe, pale outer stripes with a slightly reddish edging on some but not on others. The underside is white-ish which I think rules out vulgaris. I didn't measure them but they were about 2/3 the size of the large black slugs also in the area. The tubercles are slightly smaller than the large black slug. The photos are of 3 individuals. I have read the note by Martin Harvey and found it extremely good, but I am still not confident about the identification.