(ABT 1816-02 OCT 1895)
Thomas Lawry Withington
| +---James Trethewy (ABT 1517-ABT 1573)
| +---Richard Trethewy (BEF 1550-)
| +---Robert Trethewy (BEF 1575-DEC 1623)
| | | +---William Hawkins
| | +---Joan Hawkins 
(ABT 1530-)
| +---Thomas Trethewy (ABT 1596-ABT 1664)
| | +---Ann Burgess (-ABT 1637)
| +---Robert Trethewy (AFT 1642-ABT 1690)
| | | +---William Jolley
| | +---Isabel Jolley (ABT 1606-)
| +---Charles Trethewy (AFT 1673-DEC 1735)
| | | +---John Scawen
| | | +---Trehane Scawen (ABT 1614-)
| | | | | +---John Trehane
| | | | +---Elizabeth Trehane
| | +---Dorothy Scawen (ABT 1653-)
| | | +---Gregory Arundell (-ABT 1653)
| | +---Dorothy Arundell
| | +---Edith Crane (-ABT 1666)
| +---John Trethewy (ABT 1700-)
| | +---Jane Williams (BEF 1683-)
| +---Samuel Trethewy (ABT 1726-MAR 1791)
| | | +---William Perkin (-1688)
| | | +---John Parkin
| | | | +---Mary ?
| | +---Philadelphia Parkin (ABT 1694-MAY 1783)
| +---Samuel Trethewy (ABT 1772-25 DEC 1828)
| | | +---Richard Hendra
| | +---Blanche Hendra (ABT 1734-JAN 1775)
| | +---Jane Murton
+---Mary Blanch Trethewy (ABT 1817-31 JUL 1888)
| +---William Bryant (ABT 1733-JAN 1796)
+---Jane Bryant (ABT 1774-13 SEP 1843)
| +---Walter Lawry
| +---John Lawrey (ABT 1703-ABT 1799)
| | +---Julyen Nanjulian
+---Thomazine Lawry (ABT 1738-)
| +---John Grose
+---Mary Grose (ABT 1707-ABT 1757)
+---Mary Bellamy