My copy of "The General Armory" (1884) has the same info as Chas. Nothing for Mathia, but two entries for Mathias.

Mathias (Lampher Court and LLangwarren, co Pembroke)
Arms – Gu three dice ar two and one, on each die six spots in front, two at top, and three on the sinister side sa
Crest – A stag trippant ppr armed or

Mathias
Arms – same
Crest – Out of a ducal cornoet a broken battle axe.