The two main devices (symbols) in the Mervin blazon are the escutcheon and demi lion. The two main tinctures (colors) are sable and argent.
Sable, the deep black so often found in Heraldry is believed to named from an animal of the marten family know in the middle ages as a Sabellinœ and noted for its very black fur 1A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Sable. In engravings, when colors cannot be shown it is represented as closely spaced horizontal and vertical lines, and appropriately is thus the darkest form of hatching, as this method is known 2Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 26. Although it may seem a sombre tone, and does indeed sometimes denote grief, it is more commonly said to represent Constancy 3The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P35.
Argent is the heraldic metal Silver and is usually shown as very pure white. It is also known more poetically as pearl, moon (or luna) 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 5A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
The escutcheon simply represents smaller shield shapes included within the shield, and its close relative, the inescutcheon is just a larger version occupying most of the field. 6A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Escutcheon There is no particular significance that can accorded to the escutcheon itself, but attention should be paid to the colour and devices that are borne upon it. The escutcheon may also be added to an existing coat of arms either as recognition of some additional honour (an escutcheon of augmentation”) or in the case where arms that are already quartered are to be combined an escutcheon with the new arms may be placed overall (an ”escutcheon of pretence”). 7Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 126 & 141
The demi-lion is a variant of the typical creature shown only from the waist upward. It can take all same poses and attitudes of its fully represented brethren and often appears to be emerging from some other device such as a fess or chief. 8A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Lion No special significance should be given to the demi appearance and it should be taken to have the same meanings and interpretations as the noble king of beasts itself.