ANOMIA. 325 



"The A. cylindrica or A. cymbiformis, is A. ephippiim, 

 taking the hollowed out boat-like appearance, in conse- 

 quence of clasping the cylindrical stalks of the Fuci. The 

 A. tubidaris is the same type, having the margins of the 

 apertures elongated to suit its condition to some irregu- 

 larity of the body on which it is fixed. The A. punctata 

 is of the same character, viz. A. ephippium, deriving its 

 papillae-like markings from the substances on which it is 

 placed. I do not know A.fornicata and A. coronata. 



" I have now noticed all the British varieties I am 

 acquainted with, and there is certainly no sculpture on 

 them of so decided a character as to pronounce specific 

 distinction ; therefore all the markings, shapes, colours, of 

 this Protean genus of varieties being inadequate for the 

 foundation of species, we must have recourse to our sheet- 

 anchor, the malacology of the animal, to assist our deter- 

 minations, and after the examination of a great number of 

 individuals, embracing nearly all the British species, we 

 can arrive at no other conclusion than a firm conviction 

 that they are all varieties." 



A. ephippium, Linnaeus. 



Destitute of natural sculpture ; no triangular cavity on the 

 under valve beneath the hinge. 



Plate LV. fig. 2, 3, 5, 7, and (Animal) Plate T. fig. 2. 



Jnomiu ephippium, Linn. Syst. Nat. ed. 12, p. 1150. — Penn. Brit. Zool. ed. 4, 

 vol. iv. p. 109, pi. 62.— Donov. Brit. Shells, vol. i. pi. 26, 

 middle fig. — Mont. Test. Brit. p. 155. — Maton and 

 Rack. Trans. Linn. Soc. vol. viii. p. 102; Dorset Catalog. 

 p. 38, pi. 11, f. 3.— Turt. Conch. Diction, p. 2.— Dithyra 

 Brit. 227, pi. 18, f. 1, 2, 3, and pi. 17, f. 10. — Fleming, 

 Brit. Animals, p. 395. — Macgilliv. Moll. Aberdeenshire, 

 p. 230. — Brit. Marine Conch, p. 121. — Brown, Illust. 

 Conch. G. B. p. 69, pi. 22, f. 1, 4. — Born, Mus. C*s. 

 Vind. p. 117. — Retzu's, Nov. Gen. p. 10. — Chemn, 



