The Descending Dove or Divine Dove Symbol

       The Holy Ghost, the dove appears in most of the early representations of scenes in Christ's life-- most frequently, perhaps, in pictures of his baptism, literally rendering the words from the Gospel of John "I saw the Spirit descending from heaven like a dove." Chapter 1:32

This Divine Dove, in a radiating aureole is from a French Miniature.

  

Dove typifying grace of the Holy Spirit descending upon Christ
in his baptism. (From a painting, "Baptism of Verrocchio," in
 Florence.)

Scriptural Reference for The Descending Dove Chrismon:

• "As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and alighting on him." Matthew 3:16 (NIV)
• "For we were all baptized by one Spirit so as to form one body--whether Jews or Gentiles, slave or free--and we were all given the one Spirit to drink. "1 Corinthians 12:13 (NIV)
• "What are you waiting for? Get up and be baptized. Have your sins washed away by calling on the name of the Lord.' Acts 22:16 (NLT)
• "For as many of you as were baptized into Christ have put on Christ."  Galatians 3:27 (ESV)

Combined Triangle, Trinitarian, Dove Symbol - Many Trefoils

This trefoil shape also includes a descending dove; a reference to Christ's Baptism.

       Trefoil (from Latin trifolium, "three-leaved plant", French trèfle, Italian trifoglio, German Dreiblatt and Dreiblattbogen, Dutch klaver, "clover", same as clubs) is a graphic form composed of the outline of three overlapping rings used in architecture and Christian symbolism. The term is also applied to other symbols of three-fold shape.

       Trefoil is a term in Gothic architecture given to the ornamental
foliation or cusping introduced in the heads of window lights,  tracery,
 panellings, etc., in which the center takes the form of a three-lobed leaf
(formed from three partially overlapping circles). One of the earliest
examples is in the plate tracery at Winchester (1222–1235). The fourfold
 version of an architectural trefoil is a quatrefoil.

       A simple trefoil shape in itself can be symbolic of the Trinity,
 while a trefoil combined with an equilateral triangle was also
 a moderately common symbol of the Christian Trinity
during the late Middle Ages in some parts of Europe.

Scripture Reference for The Trinity Symbol With Dove:

• "But the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you."John 14:26 (ESV)
• "Peace I leave with you; my peace I give you. I do not give to you as the world gives. Do not let your hearts be troubled and do not be afraid." John 14:27 (NIV)
  

Above and below, more Trefoil Triangle verions.