34 ANOMIlfhE. 



tally detached from oysters in an adjoining bed, to which 

 they were originally affixed, and being thus deprived of 

 their plugs, as well as of the power to make new ones, 

 they filled up the openings with a shelly substitute, for 

 the sake of protection against starfishes and other ene- 

 mies. Having lost their own plugs, they were well 

 satisfied by being securely moored to the bed by the 

 strong cables of their friendly neighbours, the mussels. 

 I dredged a specimen of the variety " squamula" off 

 Croulin Island, Skye, which was free, but had the orifice 

 completely closed in the same way as the Welsh exam- 

 ples. The A. iubularis of Turton is a young specimen 

 of the same variety, in which the orifice had only been 

 partially closed. Old Martin Lister was well acquainted 

 with the typical form, and gave an excellent figure of 

 it in his ' Historia Conchyliorum.' 



2. A. patellifor mis *, Linne. 

 A. patelliformis, Linn. Syst. Nat. p. 1151 ; F. &II. ii. p. 334, pi. lvi. f.5,6. 



Body resembling that of A. ephippium, but the colour is 

 deeper : mantle thinner : cirri of unequal length and size, and 

 capable of considerable extension, some of them being a quarter 

 of an inch long ; they are minutely and closely ringed, and a 

 dusky line runs down the middle of each. No other part of 

 the animal is visible outside. 



Shell round or sometimes longitudinally oval, usually flat- 

 tened, thin, rather glossy towards the beak, but elsewhere of 

 a dull appearance : sculpture, fine and close-set imbricated 

 scales, and 20-30 blunt ribs which radiate from the beak in 

 every direction towards the margins in a wavy manner ; lines 

 of growth irregular : colour yellowish- white, with frequently 

 reddish-brown but not continuous streaks or spots : margins 

 thin , scalloped or notched by the ribs, nearly straight behind : 

 beak small, rather prominent, very seldom reaching to the 

 hind margin, and never overlapping it : cartilage short and 



* Shaped like a Patella, or limpet. 



