216 PANDORID.E. 



derable attention, and has been more or less completely 

 noticed by Philippi, Deshayes, and Gray. ^Ve have 

 ourselves examined it in its living state in the British 

 seas, and as long ago as 1835, it was carefully observed 

 by Mr. Clark. It is oblong, and of a yellowish white hue. 

 The mantle is closed throughout, except where there is an 

 opening towards the anterior extremity for the passage of 

 a white linguiform foot, flat and straight, long, rather 

 pointed, and marked by a byssal groove, Deshayes has 

 observed a byssus. Posteriorly the mantle forms two 

 short tubes, which are united nearly to their orifices. 

 These tubes are white, speckled with minute black dots. 

 Both have about twelve cirrhi around their openings. 

 The labial palpi are narrow, and plicated on their internal 

 surfaces. According to Mr. Clark, there is only one elon- 

 gated branchial leaf on each side, attached to the dorsal 

 range, and running straight to the tubes. Each leaf is 

 divided into two equal parts by a depressed groove or 

 furrow, and is coarsely pectinated and doubled upon itself 

 on the inner surface, rather more than half-way up its 

 height, the extent of the duplication being marked by the 

 external furrow. In consequence of this arrangement, 

 each branchial lamina, though really single, appears as if 

 it were one-and-a-half on each side. 



The finest specimens we know of are those dredged off 

 Weymouth, (near Portland,) which measure fully an inch 

 and three-quarters in length, and seven-eighths of an inch 

 in breadth. The species is likewise taken at Cullercoats, 

 near Newcastle (Alder); at Scarborough (Bean); in 

 twenty-seven fathoms, the Coquet (Thomas); in fifteen 

 fathoms West Bay of Portland, and twenty-five fathoms 

 Penzance Bay (M'Andrew and E. F.); in fifteen to 

 twenty fathoms Isle of Man (E. F.). 



