3362 Mollusks. 



which causes it to be washed ashore. It is not so often found in win- 

 ter, the Ulva being an annual. 



Mactra subtruncata buries in sand, and may often be found at low- 

 water spring tides, on the Smallmouth Sands, having worked its way- 

 out of the sand, in the same manner as the solens are in the habit of 

 doing upon the ebb of the tide. 



Mactra stultorum. Frequently very common in Weymouth Bay 

 after storms. May 15, 1850. — At low water this evening they were 

 very numerous, the tides at the spring ; they seemed to live here ei- 

 ther lying about on the sand or buried in it, and had not been washed 

 in from deeper water by rough seas, as the sea had been perfectly 

 calm for many days previously. Most of them were about half grown, 

 and I do not recollect having before or since obtained them in this 

 intermediate state of growth. After very rough seas, I have found 

 very minute young specimens by thousands on the Smallmouth Sands, 

 although, strange to say, I have never found adult specimens here in 

 any abundance, if I have taken them here at all. 



Tapes pullastra. Sometimes very abundant in Weymouth Bay 

 after storms. 



Tapes aurea. Washed up by storms on the sands in Weymouth 

 and Smallmouth Bays. In the early part of April, 1850, after strong 

 easterly winds, they were very abundant. 



Venus striatula. A most abundant mollusk here, both in Wey- 

 mouth and Smallmouth Bays, and may be found almost every day in 

 the latter locality at low tide. 



Lucinopsis undata is sometimes washed up on the Smallmouth 

 Sands, both alive and dead. 



Cardium echinatum. March 16. — Yesterday the wind blew strongly 

 from the eastward, and upon the Smallmouth Sands this day I found 

 many marine objects strewed about, amongst which were some very 

 large specimens of this species ; one of them measured 9|- inches in 

 its longitudinal circumference, and lOj inches in its transverse cir- 

 cumference. Very young and beautiful live specimens may likewise 

 be found at times on the above sands. 



Cardium rusticum. February 26, 1850. — This day I found a fine 

 specimen alive on the Smallmouth Sands, it having been but recently 

 washed up. It was on the sand at very low-water spring tides, in a 

 similar situation to that mentioned in Messrs. Forbes and Hanley's 

 British Mollusca on the Paington Sands, Torquay. As a British 

 species it is essentially local. 



