1		They founded Plymouth (US) in 1620 (7,7)
8		Co-conspirator, with Cassius, against Julius Caesar (6)
14		Seafarer's waterproof headgear (3-6)
15		British dialect often regarded as pretentious (6,7)
16		Hungarian composer of symphonies Faust and Dante (5)
17		Concluding (5)
18		Blood poisoning (11)
19		Halfhearted (8)
21		Popular holiday island of the Balearics (7)
23		Showiness, especially of a tawdry manner (5)
24		Farewell drink traditionally given to a horseman (7-3)
26		Ancient form of capital punishment (11)
28		Grouping of directional antennae (5)
29		Russian city also known as Tsaritsyn (9)
30		Event considered by some as marking the origin of the universe (3,4)
32		Imprecise (variant spelling) (7)
34		Designed for ease of physical use (9)
36		Small hill of South Africa (5)
37		The squire of Don Quixote (6,5)
40		Native to the Antipodes (10)
41		Ancient Nile city famous for its dam (5)
42		First name of "pudding and pie" nursery rhyme character (7)
44		Lady's perfume box (8)
46		Someone on their way to 26 across? (11)
49		Medical word for openings (5)
51		Type of PC racing game "power- up"
52		Product feature not included within basic cost (8,5)
53		A good hand in bridge (5,4)
54		Castrated male (6)
55		Site of Edward Kennedy's car crash in 1969 (14)

1		Grinding tool associated with mortar (6)
2		Old French architectural style (5,8)
3		Electromagnetic radiation beam (8,3)
4		Musical theme (5)
5		Pertaining to plant and soil sciences as applied to crop production (11)
6		Thug (7)
7		Guardian crossword pseudonym of Roger Squires (5)
9		Afro-Caribbean dance music variety (5)
10		One of a group of ancient Roman administrators (9)
11		Austrian-born actor and US Governor (14)
12		Dress with full-length opening (10)
13		Meat or seafood marinated in soy sauce (8)
20		Scandinavian alcoholic drink often flavoured with caraway seeds (7)
22		Rosewood tree native to Brazil (9)
23		Norwegian composer of the Peer Gynt Suite (5)
25		North Korea's capital (9)
27		Swiss composer credited with the invention of eurythmics (6-8)
30		Glued fabric used in bookbinding (7)
31		Second closest star to Earth (5,8)
33		Very pale (5)
34		Irish author of "The Country Girls Trilogy" (4,6)
35		Geographical area between the Euphrates and Tigris rivers (11)
36		Russian city, formerly Konigsberg (11)
38		City of NE Texas, in Bowie County (3,6)
39		Untreated ore (3,5)
43		Fruit skin (7)
45		One of 7 spacecraft launched by Russia from 1961 (6)
47		Disciple of Greek philosopher Zeno, marked by lack of emotion (5)
48		Unsuccessfully attempt to vomit (5)
50		Former French province in the Loire valley (5)