350 MARSHALL: ADDITIONS TO “‘ BRITISH CONCHOLOGY.” 
Conchology”; but all the British specimens I have seen 
are more regularly rounded and produced at the posterior 
side. The microscopic sculpture is similar to that of Zepton 
clarki@. Sowerby’s figure is more like British specimens, 
but the beaks are too prominent and acute, and the colour 
should be pale-horn ; they agree in all other respects. 
M. donacina S. Wood.—Falmouth and Shetlands (Jeffreys) ; 
Lough Swilly (‘Porcupine’) ; Torbay. 
A very rare species. It is of such a peculiar shape that 
once seen it would readily be known again. A Coddington 
lens shows very fine concentric striae and numerous lines of 
growth. Searles Wood’s figure is a very good one, but 
Jeffreys’ and Sowerby’s are only sufficient to indicate the 
outline. 
M. ferruginosa Mont.—This species has been previously fully 
treated by me.’ Occasionally, and in a good light, inter- 
rupted longitudinal rays may be seen, but not nearly so 
marked as in Zed/imya nivea Sars, a variety of this species, 
which is distinctly rayed. Jeffreys’ figure is too angular ; 
it should be more rounded at each end. | Sowerby’s is too 
truncate at the smaller end, and it shows a conspicuous 
brown epidermis round the margins, which is incorrect ; it 
is very often covered with a thick ferruginous deposit, but 
that is always confined to the uppper margin and umbonal 
area. 
Var. ovata n. var.—Shell depressed, broadly oval, and 
shorter ; beaks more central and less prominent. Kyles 
of Bute, 18 f. ; Gairloch, 30 f.; Minch off Loch Boisdale. 
Not JZ. ovata Jeff. 
M. dawsoni Jeff—Dingle Bay, 30—4o f. (« Porcupine’); _ 
Scilly, 40 f£., a perfect specimen (Burkill and J.T.M.); 
Torbay; Bantry Bay; Donegal coast; Bartra Island ; 
West Orkneys, 45 f. Also Newfoundland (Verkriizen) ! 
1. J. of Conch., vol. 6, pp. 399—404. 
J.C., vili., Jan., 18 97. 
