Shells found in Essex County. 131 



Mactra lateral is, G. Abundant in the muddy bottom of 



the tide-mill pond, Salem, W. 

 Margarita arctica, G. Salem, Tr. 

 Margarita argentata, G. Off Cape Ann. Gould, 256. 



Lynn beaches, Tr. 

 Margarita obscura, G. Beverly harbor, Agassiz. Off Egg 



Rock, near Nahant, T. &. H. St. Sh. 31. 

 Margarita undulata, G. Alive on Phillip's beach, Gould, 



254. 



Menestho albula, St. Pyramis striatula, Couth. Vicinity 

 of Cape Ann, Couthouy. Gould, 269. Off Baker's 

 Island, Wheatland, St. Sh. 40. 



Mesodesma arctata, G. Off Nahant, Gould 57. Abun- 

 dant at Plumb Island, near Newburyport, W. 



Nassa trivittata, Say. Buccinum trivittatum, G. In abun- 

 dance at Phillip's beach in a living condition. Dr. Pres- 

 cott, Gould 309. 



Natica flava, G. One specimen, Salem, Tr. 



Natica immaculata, G. Salem harbor, W. St. Sh. 43. 



Natica pusilla, G. Stomachs of fishes off Half-way rock,W. 



Nncula delphinodonta, Mighels. Off Cape Ann, St. in 

 Bost. Proc. iv. 13. 



Osteodesma Hyalina, G. Salem, Tr. 



Paludina decisa, G. Common in ponds and fresh water 

 streams in Essex County. 



Pandora trilineata, G. Beaches at low water, W. In a 

 living condition, Lynn beaches, Tr. 



Pecten Magellanicus, G. Orne's Point and Beverly Bar,W. 

 Philine formosa, St. in Bost. Proc. iii. 334. Off Cape Ann. 



Pleurotoma bicarinata, G. Off Nahant, Couthouy. Lynn, 

 Dr. Prescott. Gould, 281, 



