40 



ANOMIA, Linnaeus. 

 A. EPHIPPIUM, Linnaeus. 



A. ephippium, Brit. Moll. ii. p. 325, pi. 55. f. 2, 3, 5, 7; and animal, 



pi. T. f. 2. 

 Anomia ephippium, A. electrica, A. cepa, A. squamula, A. aculeata, 



A. striolata, A. punctata, A. cylindrica, A. tubularis, A.striata, 



A.fornicata, A. coronata, A. patelliformis, A. undulata, Aucto- 



rum. 



A. aculeata, Brit. Moll. ii. p. 332, pi. 55. f. 4. 

 A, patelliformis, Brit. Moll. ii. p. 334, pi. 56. f. 5, 6. 

 A. striata, Brit. Moll. ii. p. 336, pi. 55. f. 1, 6, and pi. 53. f. 6. 



Animal subdepressed, with its periphery suborbicular ; 

 mantle circular, the upper portion, or the one forming the 

 convex valve, of very thin and pellucid texture, except at the 

 anterior margin, which is thick ; and the under part, or that 

 lying on the flat valve, is also thin, hut has the appearance of 

 being fleshy from having the ovarium soldered to it ; both are 

 clothed with a double fringe, which diminishes in breadth as 

 it approaches the beaks, and passes round the aperture of the 

 operculum, there throwing out cilia, and then is fixed under 

 them. The outer circle of fringe consists of long, yellowish 

 white, sharp-pointed tentacular filaments, which are, when 

 undisturbed, continually protruded beyond the shell, and on 

 the inner circle there are long and short cilia of the same 

 colour distributed irregularly ; but the colours of the fringes 

 and their marginal areas vary from a mixed blotchy red to 

 yellow or purplish brown. No ocelli can be detected. There 

 are a pair of circular branchiae varying from pale red to dark 

 brown on each side of the body, with fine longitudinal and 

 transverse vessels, presenting the appearance of a delicate net- 

 work ; the plates of each pair have a part of their outer sur- 

 faces double, and form circular open pouches, the upper part 

 of which is well defined by the branchial vein : thus each single 

 plate presents the aspect of two, and the two pair of branchiae 

 appear composed of eight plates; but the doable parts can 

 easily be placed in length, by the insertion of a camePs-hair 

 brush in the hollows, and again be returned to the double 



