The arms are those of Spry, as borne by the descendants of Rear Admiral Sir Richard Spry (1715-1775), naval captain and Commander of the sloop Comet Bomb.
Richard Spry is well known in the field of American silver as the recipient of the massive "Comet Bomb" silver presentation cup by Jacob Hurd. The cup was presented to Spry by a group of Boston merchants after he captured a French privateer in 1744. (See David B. Warren, et al., Marks of Achievement: Four Centuries of American Presentation Silver, cat. no. 57, pp.57-59.)
For a biography of Spry's distinguished naval career, see Laurence O'Toole, The Cornish Captain's Tale, 1986 (a copy accompanies this lot).