Hi Tim,
the function you are asking for is Flatten:
llist = {{16.3516, 17.3239, 18.354, 19.4454, 20.6017, 21.8268,
23.1247, 24.4997, 25.9565, 27.5, 29.1352, 30.8677}, {32.7032,
34.6478, 36.7081, 38.8909, 41.2034, 43.6535, 46.2493, 48.9994,
51.9131, 55., 58.2705, 61.7354}};
Flatten[llist]
But in this case you could use Join like so:
Join @@ llist
Regards -- Henrik