ON SOME MARINE MOLLUSCA. 151 



from its fresh appearance there could be no doubt 

 that it had been voided in the bay by some bird. 



We all know that many of our British shells are 

 common to European seas far apart; and when we 

 consider the many favourite molluscan retreats and 

 pastures extending along the submerged weedy rocks, 

 which form the rich feeding - ground of many sea- 

 birds, but are never attempted to be touched with the 

 dredge, we may reasonably expect that when suit- 

 able appliances are brought into use many valuable 

 treasures will be brought to light which have never 

 been supposed to exist in such j)laees. The great 

 facilities which have recently been afforded by Mr. 

 Coulson's yacht, and the Medusa from the Gran ton 

 Marine Station, both steam-vessels fitted up with the 

 latest improvements for dredging purposes, have 

 enabled new light to be thrown on the Fauna of 

 the Firth of Clyde and West of Scotland. 



Although many of the species have been taken 

 sparingly and considered rare, Ave have hitherto had 

 but an obscure idea of the precise location of their 

 real home. Pectcn septemradiatus, for example, was 

 at one time thought to be rare in the Firth of 

 Clyde, and brought a high price. I have been 

 informed by Dr. J. R. Henderson (now of Madras) 

 that some of the English dealers still ask half-a- 

 crown for a single specimen. This species is said 

 to frequent rough stony ground, but, so far as the 

 dredgings of the Medusa have shown, its home is 

 on a mud bottom. There, at a depth of 50 or HO 

 fathoms, it is not unusual to meet with a dozen or 

 two at a haul. On one occasion, when in company 

 with Mr. Murray in the Medusa, between C umbrae 

 Light-house and Arran, in 80 fathoms, bottom soft 

 mud, Ave brought up at one haul above 300 living 

 specimens of this shell. 



Many years ago I dredged off Cumbrae the shell 

 Siphonentalis lofotensis, which is noticed by Mr. 

 Alfred Brown in his Mollusca of the Firth of Clyde. 

 Last summer I found the same species moderately 



