Another crab, equally common with those already mentioned, is to be met with when dredging, and in most rock-pools. At Wardie, near Edinburgh, I have seen hundreds of all sizes hiding beneath the rocks at low tide. Its scientific name is _Hyas araneus_, but it is better known as one of the Spider-Crabs. It claims close relationship with that noted crustaceous sanitory reformer, _Maia squinado_. Although this H. araneus is a somewhat pleasant fellow when you get thoroughly acquainted with his eccentricities, appearances are sadly against him at starting. Speaking with due caution and in the gentlest manner possible, consistent with truth, I must say that this crab is, without exception, one of the dirtiest-looking animals I have ever met with in my zoological researches. At a by no means hasty glance, he appears to be miraculously built up of mud, hair, and grit on every part, except his claws, which are long and sharp as those of any bird of prey. The first specimen I ever saw, seemed as if he had been dipped in a gum pot, and then soused over head and ears in short-cut hair and filth. The second specimen, although equally grimy, had some redeeming points in his personal appearance, for at intervals every part of his back and claws were covered with small frondlets of ulva, dulse, _D. sanguinea_, and other beautiful weeds, all of which were in a healthy condition. After keeping him in a vase for a week, he managed, much against my wish, to strip himself of the greater part of these novel excrescences. Instead of minute algæ, we read that these crabs are sometimes found with oysters (_Ostrea edulis_) attached to their backs. Mr. W. Thompson mentions two instances where this occurs, with specimens of _H. araneus_, to be seen in Mr. Wyndman's cabinet. Speaking of these, he adds, 'The oyster on the large crab is three inches in length, and five or six years' old, and is covered with many large Balani. The shell, a carapace of the crab, is but two inches and a quarter in length, and hence it must, Atlas-like, have born a world of weight upon its shoulders. The presence of the oyster affords interesting evidence that the Hyas lived several years after attaining its full growth. For days after I had brought him home, my second specimen appeared as if he were dead, and it was only by examining his mouth through a hand lens that I could satisfy myself as to his being alive. When I pushed him about with an ivory stick he never resisted, but always remained still upon the spot where I had urged him. This species of _acting_ he has given up for some time, and at the present moment I rank H. araneus among my list of marine pets, for he does not appear any longer to pine for mud with which to decorate his person, but is quite content to 'purge and live cleanly' all the rest of his days.