354 MARSHALL: ADDITIONS TO ‘“‘ BRITISH CONCHOLOGY.” 
“British Conchology”—“‘Skye and Shetland, 45—85 f., 
rare,” has been considerably amplified. It is pretty gene- 
rally distributed throughout the Clyde and Hebrides on very 
muddy ground, but to obtain it the dredger must not be 
afraid of laboriously sifting plenty of mud—material which 
is usually thrown away by him in disgust. The shell is 
usually encrusted with ferruginous matter on each side of 
the beaks. It is very constant in form, and does not vary 
at all except in size. 
In 1886, on looking over some young 4. flexuosus 
dredged on the Doggerbank ten or twelve years previously, 
I picked out half-a-dozen A. croulinensis from among them. 
This locality is remarkable as being much further south 
than the next nearest record, and the only one for the 
English coast. I regret I did not observe the species when 
dredging, and so fix the exact locality. 
All the Hebridean specimens are of small size, less than 
one-half the dimensions given by Jeffreys ; but the Dogger- 
bank specimens are much larger, corresponding to the 
Norwegian form in point of size, which is only exceeded 
by a pair of original Shetland valves given me by Dr. 
Jeffreys. 
A. ferruginosus Forb.—ro to roof. in muddy sand. Gairloch, 
30 f.; Sound of Sleat, zo—gof.; Loch Hourn, 25 f. and 
75 f. (Somerville and J.T.M.); Tarbert, 20 f. ; Inverary and 
other parts of Loch Fyne, 22—56f.; Stornoway, tof. pethie 
Minch off Barra, 50 f. Abundant in most of these localities. 
Mr. Alfred Brown’ states that this ‘is one of the 
dredger’s prizes . . and is exceedingly scarce”; but I have 
found it far otherwise. It is a gregarious species, and 
especially abundant in some parts of Loch Fyne. They 
come up in the dredge like little globules of mud, no part 
of the shell being visible. The young are unlike the adult 
shell, and resemble 4. cycladius. 
1. Mollusca of the Firth of Clyde, p. 109. 
J.C., viii., Apr. 1897. 
