5. N.Y.C. & Boston transit systems, initially

9. "Don't give me that!"

14. Enlist in

15. Light

16. Bring up

17. Ancient

18. Heavily involved

20. Isuzu model

22. Tide variety

23. Blue

24. Blows it

27. Attraction

29. ChapStick, e.g.

32. Wall Street figure

36. Radiate

37. Put in place

39. High nest (var.)

40. Pro follower

41. Ice cream flavor

43. Arp's art

44. Stradivari's mentor

46. Tex-Mex snack

47. Kind of column

48. Microwaves' inner works

50. One who's lost his mate

52. Commuter line

54. Beach bird

55. An end to sex?

58. Russian autocrat (var.)

60. Decree

64. One end of the pool

68. Hairy twin in the Bible

69. In-box contents

70. Dwarf buffalo

71. The "E" of B.P.O.E.

72. Miser's fixation

73. Stupefy, slangily

74. Cheat, in a way

1. Slightly cracked

2. Canceled

3. Laced

4. In a difficult situation

5. Dr. with a dream, initially

6. Go for the bronze?

7. "Absolutely!"

8. Floor it

9. Set up

10. Oil-can letters

11. Rose fruit

12. Largest of the seven

13. Make one's way

19. Blowgun ammo

21. Sun, e.g.

25. Coarse file

26. Cold shower?

28. Place for a strong feeling

29. Andean animal

30. Bits

31. Avian chatterbox

33. Cover, in a way

34. Duck to get you down?

35. Peruse

36. Mama's mama

38. Implied

42. Central point

45. In a hoppingly mad manner

49. King or queen, e.g.

51. Lode load

53. Capital of Bolivia

55. Any thing

56. Jerk

57. Hard-hearted

59. City near Lake Tahoe

61. Dot in the drink

62. Harden

63. Ivory source

65. Conk out

66. "Smoking or ___?"

67. Former U.S. terr.