(sect, d), balanus patellaris. 259 



specimens on crustaceans, on rocks, and even on the roots of the larger 

 sea-weeds. This species is very common in the glacial deposits of 

 Uddevalla, of Skien in Norway, and of Canada, and is associated with 

 the same species as in the living state : I have seen, also, specimens from 

 the same formation in the Island of Bute, Scotland. I have seen 

 numerous specimens from the mammaliferous crag, and a few from 

 the Red Crag of England. I owe to the kindness of Mr. J. de C. 

 Sowerby an inspection of the original specimens of the B. tesselatus of 

 the Mineral Conchology, which is certainly the present species. 



Affinities. — This species is very distinct from every other ; it comes 

 nearest, as shown in all the characters derived from its opercular valves, 

 to B. nubilus, and in this latter species we have seen the basis plainly 

 tending to lose its pores and thus become solid. B. porcatus is perhaps 

 allied in some degree to B. trigonus, and slightly to B. crenatus. The 

 rather broad radii, with their summits hardly oblique, give this species 

 a very different aspect from those species of the genus amongst which 

 it must be placed. 



Varieties : a conical specimen, sent to me from the coast of Massa- 

 chussetts, is remarkable from the radii not having been at all developed, 

 being represented by mere fissures. I have seen a few specimens of 

 var. (a), (one collected by Sir E. Parry in the arctic seas) which had a 

 remarkably different aspect from the common forms, but w r hich, after 

 a careful examination of the opercular valves and of the animal's body, I 

 feel convinced are not specifically distinct : they are characterised by the 

 walls being smooth and absolutely destitute of the external longitudinal 

 ribs; by the shell being more cylindrical, with broader radii, and with 

 the orifice larger and more rhomboidal ; the walls and radii are much 

 thinner, and the internal lamina is less plainly ribbed : the beak of the 

 tergum is not purple. As most of these specimens had grown in a 

 group crowded together, the difference of shape, and perhaps the thin- 

 ness of the walls, is thus explained. In a specimen from Davis's Straits, 

 in Mr. A. Hancock's collection, most of the above characters are in an 

 intermediate condition ; there are only a few external longitudinal ribs 

 on the parietes; and the terga have not purple apices. In Mr. Cuming's 

 collection there are some fine, brilliantly white specimens (ivithout 

 opcrcula) from the coast of China ; these have thin walls and radii, 

 and the walls are not longitudinally ribbed, but they are not smooth : 

 the orifice is not large, nor the shape of the whole shell cylindrical. 

 It is just possible that these latter specimens may be a distinct and 

 representative species, but I do not think so. 



26. Ealanus patellaris. PI. G, fig. 5 a — 5 c. 



Lepas patellaris, (Gmelin). Spengler. Schriften der Berlin. 



Gesellschaft, &c. b. i (1780), Tab. 

 5; Chemnitz, Neues Syst. Conch., 

 Tab. 98, %. 839. 



Shell depressed; brown, generally with obscure longitudinal 



