Sentence:  "Martlet", or <WSD>"merlion</WSD>", a fabulous bird, of constant adoption in armorials, shaped like a martin or swallow, and always drawn without legs, with short tufts of feathers instead, divided into two parts, somewhat like an erasure, and forming, as it were, thighs. This is the distinctive mark of the fourth son. 
Meaning of the word marked with <WSD> tags:  (heraldry)  A depiction of a bird similar to a house martin or swallow with stylized feet; a martlet. (from late 15th c.)