MODIOLA. 191 



central well-marked but rounded off obtuse angle with the 

 upper posterior outline, which is but little arcuated ; the 

 hinder extremity is very broad, and rather more prominent 

 above than below. The ventral margin is often much in- 

 curved, and there is a decided projection of its posterior 

 end beyond the general outline. The internal surface is of 

 a subnacreous white, and often stained with purplish rose- 

 colour at the upper portion. 



The breadth of a fair sized specimen was one inch, and 

 its length an inch and a half. 



The animal of Modiola harhata was observed by Poli, 

 and has recently been examined by Mr. Clark, during the 

 autumn of 1 848 ; he describes it as elongated, thick, 

 mantle freely open and for some little depth, with double- 

 edged reddish-brown margins. The body is large, sub- 

 rotund, and brown ; from it spinngs a byssal foot, with a 

 large cavity in the hinder part for a fine bushy dark 

 byssus ; the remainder of the foot is finger-shaped, not 

 pointed, white, and longitudinally grooved. The branchise 

 are brown and narrow ; the upper leaflet of each pair is not 

 half the depth of the lower. There are no tubes nor orifices 

 in the mantle, and the branchial laminae are continued 

 close to the posterior extremity. The palps are reddish- 

 brown, long, flat, strongly striated transversely on the 

 inside, and smooth on their outer surfaces. 



This is one of our rarer British shells, and essentially of 

 a southern character. At Gorey, in Jersey, we have seen 

 the beach strewed with them to the depth of some inches, 

 at a spot where the rejectamenta of the oyster-fisheries were 

 wont to be deposited (S. H.) ; but on the English coast 

 individual specimens are much prized. It is taken, but 

 rarely, at Torbay (Mrs. Griffith) ; Exmouth (Mr. Clark) ; 

 oif Portland in fifteen fathoms, Weymouth in nine 



