54 



striata, albida, epidermide fusco ; natibus 

 depressius culis. Lon. ^n ; Lat. y^^y. 



Shell ovato-oblong, almost aequilateral, with obso- 

 lete transverse striae ; white, covered with a brown 

 epidermis, which is worn away at the upper part of 

 the shell, but bears the traces of regular transverse 

 striae towards the margin ; the anterior extremity is 

 slightly truncate, the posterior rounded ; beaks de- 

 pressed ; translucent. In form, this species resembles 

 Corbula rosea, but is more elongated transversely. 

 The teething is very similar 



Taken from the root of a fucus cast on shore at 

 Ballaugh. 



LXXIX. Mya, Lin. 



1. truncata, Lin. 



Dead valves are not uncommon on the north coast. 



2. Swainsoni. 



Sphenia Swainsoni, Turlon. 

 In roots of sea weeds, and cavities of dead shells ; 

 not uncommon. I am aware that this shell is consi- 

 dered by some of our best conch ologists to be the 

 young of Mya arenaria. After a careful comparison 

 of undoubted specimens of the young Mya arenaria 

 with my Manx shell, I am induced to consider the 

 latter distinct, — a conclusion which the absence of 

 Mya arenaria from the Manx shores would go far to 

 confirm. 



LXXX. Lutraria, Lam. 



