BYXE : MARIXE MOLLUSCA OF TEIGXMOUTH. I 79 



Gastrochsena dubia Penn. A single live specimen from 

 the centre of a loose block of limestone occupied by a 

 large number of Saxicava rugosa. Also several live 

 specimens from blocks of rock brought in by trawlers 

 which have been compelled to come in, their trawl nets 

 being broken. The valves being so fragile and lightly held 

 together, it is often desirable to preserve the shell with the 

 animal in it. 



Pholas dactyl us L. A few obtained alive at low spring 

 tides from the rocks here, the largest measuring four-and- 

 a-half inches long. The syphon of this animal was fully 

 extended when first observed, but, after throwing up a 

 cascade of water, it disappeared, and the shell was only 

 found again by pickaxing more than twelve inches beneath 

 the surface of the sandstone. The shell was dark shagreen 

 in colour. This species is almost extinct here. 



P. Candida L. Does not occur so often as P.parva. 



P. parva Penn. Have been common, but fine examples only 

 in the reefs of rock at lowest spring tides. 



Pholadidea papyracea Turt. A few live and dead adult 

 and young examples from hard red sandstone rocks. 



P. papyracea var. aborta Jeff. One example with the type. 



Teredo norvegica Speng. Some live examples in a large 

 piece of timber brought in by a trawler whose net had got 

 fouled in part of an old wreck in the bay. 



Dentalium entails L. A few small and dead examples on 

 the beach. 



Chiton fascicularis L. A few in clefts of rocks, and 

 amongst stunted mussels on the rocks, no doubt attracted 

 by the excreta of the mussels. 



C. marginatus Penn. Under -smooth stones and amongst 

 rocks between tide-marks. 



Patella vulgata L. Common. 



Helcion pellucidum L. Adult and young specimens 

 amongst the roots of Lamellaria saccha7'i?ia. 



