34 ANOMIID^. ' 



tally detached from oysters in an adjoining bed, to which 

 they were originally affixed, and being thus deprived of 

 their plugs, as w T ell as of the power to make new ones, 

 they filled up the openings w r ith 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. tubularis of Turton is a young specimen 

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

 partially closed. Old Martin Lister w r as well acquainted 

 with the typical form, and gave an excellent figure of 

 it in his ' Historia Conchvliorum.' 



2. A. patellifor mis *, Linne. 



A. patelliformis, Linn. Syst. Nat. p. 1151 ; F. &IL 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 : 

 bealc small, rather prominent, very seldom reaching to the 

 hind margin, and never overlapping it : cartilage short and 



* Shaped like a Patella, or limpet. 



