53 



AQUATIC MOLLUSC A. 



Class I. CONCHIFEEA, OR BIVALVES. 



Order Lamellibranchiata. 



Fam. Splicer idae. 



Sphcerium cornenm, L. Abundant. Specimens fine, and most of them very 

 dark coloured, especially the largest specimens. I have obtained 

 the finest shells in a pond at Corby, one of which is 0"5" in breadth. 

 In Rickerby Beck, and also in ponds near the Eden at Rickerby, 

 both dark-coloured and paler specimens are found. Other localities 

 are — the Eden, Petteril, and a pond in the Willow Holme, 

 var. flavescens, Macgill. I have taken this in the Derwent at Peil 

 Wyke. Capt. Brown, in his "Land and Fresh- water Conchology," 

 says that a small, pale lemon- coloured variety of S. corneum has 

 been foimd by Mr. Glover in the Leven, near Ambleside, which I 

 think must be this ; but I have not had an opportunity of searching 

 for it there. 



S. lacustre, Mull. Finest specimens in ponds at Rickerby and Blaithwaite, 

 smaller ones in a pond at Corby. "Ullswater and a pond at 

 Corby." (Capt. Brown.) 



Piaidium amnicum, Mull. Abundant in the dam at Denton HiU, and in 

 Rickerby Beck. In the latter I have obtained the finest specimens, 

 one of which is 0'45" in breadth, length 0'35". 



P. fontinale, Drap. Abundant in a pond at Blaithwaite. 



P. pusillum, GmeUn. Common. Wreay, Rockclifife, Blaithwaite. 



P. nitidum, Jenyns. Ditch at Dalston ; in Wreay Wood. 



P. roseum, Scholtz. Pond at Blaithwaite. 



Fam. Unionidce. 



Unio pictorum, L. River Brathay, near Ambleside. (Capt. Brown.) 

 U, margaritifer, L. River Irt. (Capt. Brown.) Pearls are frequently 

 found in this mollusk, and Camden says that Sir John Hawkins 

 had a patent for fishing pearls in the Irt. 

 var. minor, Rossm. Capt. Brown states that this variety is found in 



the Mint at Kendal, 

 var. arcuata. Brown. In the Derwent, Bassenthwaite. (Capt. Brown. ) 

 var. olivacea. Brown. In the Leven, a little way below Windermere 

 Lake. (Capt. Brown.) 

 Atwdonta cygnea, L. In the River Petteril at Wreay. The shell is 

 remarkably solid even in young specimens ; it seems to approach 

 the var. incrassata, Shepp. 

 var. zellensis, Gmelin. Borrowdale. (Capt. Brown.) 



