208 DUBLIN UNIVERSITY 



Psammobia vespertina (Chemnitz). 

 One valve only occurred in the sandy mud. It is of the full-grown 

 size. This species is likely still an inhabitant of the harbour, if I may 

 conclude so from a fine fresh specimen of the shell, with valves united, 

 which I found at low-water mark at Dalepoolin ; but it has not been 

 dredged in the bay, as it is not mentioned in Mr. Hyndman's Report. 



Psammobia Ferroensis (Chemnitz). 

 Was not scarce in the deposits, but occurred only in single valves. 

 The full ordinary size of the species in the recent state was nearly 

 reached. It is now dredged in the bay, in the dead state, but with 

 valves united. 



Tellina tenuis (Da Costa), 

 Was represented in the sandy deposits by rather fresh-looking spe- 

 cimens, in some degree preserving their glossy and tinted surface. It 

 is one of the mollusca found off the harbour at present. 



Tellina fabula (Gronovius). 

 Occurred in the light-house bed. Has not been taken living, though 

 a likely inhabitant, from the freshness of the shells met with on the 

 shores of the bay. 



Tellina solidula (Pulteney). 

 This species was distributed everywhere in great abundance through- 

 out the beds, and many of the individuals preserved their bright internal 

 colouring. It is still a common shell among those living in the neigh- 

 bourhood. 



Syndosmya alba ( Wood). 

 The shells of this species, so long known by the subsequently be- 

 stowed epithet Boysii, were very common in the sand and mud, being 

 well distributed, and occurring in large numbers in company. They 

 were generally of good size, the measured length of one specimen being 

 -f£ths of an inch, and its breadth -^ths of an inch. It is in the recent 

 state also an inhabitant of the bay. 



Scrobicularia piperata ( Gmelin). 

 This species, the Lutraria compressa of Lamarck, has left ample 

 memorials of itself in the blue clay of the deposits. The samples were 



