5710 Molluscs. 



Fam. II. Gastrochcenida. 



Saxicava arctica (Hiatella arctica, mimita and prtecisa, Avatina 

 arctica). This species is frequent in all parts of the Clyde district, 

 and may be taken either by the dredge, or in rock-pools among the 

 roots of Corallina. 



* „ rugosa {Saxicava Pholadis). In similar situations to the 

 last, but more common. 



Fam. III. Myadce. 



*Mya truncata (My a ovalis, Sphenia Swainsoni). Is common in 

 most of the sandy bays throughout the district. Specimens, in fine 

 condition and of very large size, may be found cast up in abundance 

 at Fintry Bay, Cumbrae, after storms. Specimens from this locality 

 sometimes measure three inches long and two and a half inches wide. 

 Dr. Landsborough mentions the variety named uddevalensis as found 

 in Lamlash Bay. 



* „ arenaria. This is a far more local species in the Clyde dis- 

 trict than is the last. It occurs in Lamlash Bay, and Mr. Alder has 

 met with it " at Rothesay Bay, where both this and truncata are used 

 by the fishermen for bait," F. fy H. 



*Panopaea norvegica (Panopcea Bivonce). This is an abundant 

 fossil in the glacial beds. Dr. Landsborough says, " the first speci- 

 men ever got in Scotland of Panopsea norvegica was found on 

 the shore at Fintry Bay, Isle of Cumbrae, and probably from the 

 post-tertiary deposits." — Lands, p. 420. The shells found in this 

 deposit are in such beautiful preservation that they might easily be 

 mistaken for recent examples. The specimen in my cabinet, for 

 which I am indebted to Mr. Smith, is from the Kyles of Bute, and 

 has the epidermis still on : I have seen such specimens placed in cabi- 

 nets as recent ; but the Panopsea has never, I believe, been taken 

 alive on the west coast. 



Fam. IV. Corbulida. 



*Corbula Nucleus (Corbula striata). As far as my observations go, 

 this is a somewhat scarce shell; I have taken it between the 

 Cumbraes, and it likewise occurs in Lamlash Bay, but in neither of 

 these places does it appear to be gregariously abundant, as it is often 

 met with elsewhere. 



Sphenia Binghami. Included iu Dr. Landsborough's list of Arran 



