REPORT ON THE TESTACEOUS MOLLUSCA. 237 



Psammobia tellinella, Lam. 

 One large and well-coloured shell taken living in Menai 

 Straits. 



Psammobia ferroensiSy Chem. 

 Valves. Occurs alive and fine, in channels at low-water, 

 near Penmaenmawr. 



Mactra solida, L. 

 Not unfrequent off Constable Bank, Menai Straits, and 

 north of Puffin Island, living, old and young, many charac- 

 teristic and fine specimens ; also, off Port Erin, Isle of Man. 



Mactra solida, var. elliptica. 

 Young, from Port Erin, and off Great Ormes Head. 



Mactra stultorurriy L. 

 With the last, but not so common or so fine. Valves 

 common on Waterloo Shore. 



Lutraria elliptica, Lmk. 

 Valves frequent at Penmaenmawr, and occur at South- 

 port. 



Scrobicularia prismatica, Mont. 

 A few valves off Puffin Island, N. 



Scrobicularia alba, Wood. 

 Living specimens rare, and dead valves frequent with the 

 last. Extremely abundant on the Ked Wharf Bay sands. 

 Sometimes, in summer, a ridge of these shells, quite fresh, 

 but without the animal, will lie on high-water mark for very 

 many yards. 



Thracia pratenuis, Pult. 

 Port Erin, Isle of Man. Dredged alive. 



Corbida gihba, Olivi. 

 During cruise of " Hyaena," six miles off Great Ormes 

 Head, fourteen fathoms. 



