Of these all that are recorded as North American species are Saxicava

arctica, Janthina communis, Lamellaria perspicua.

The following species are common to Madeira, and Scandinavia.

Total 34 in 156, or 21 per cent. of Madeira species common to Scandinavia.

Madeira possesses, in common with the British seas

Total of Madeira species common to the British seas, 69 in 156, or 44 per cent.

All the species common to Madeira and Britain are likewise to be found in the Mediterranean and Lusitanian district, with addition of the following:

Making of Madeira species common to the Mediterranean and Peninsula;

All the Madeira species were obtained in the Canary Islands, except

the following:-