Hello Paolo
Here is the bibliography of what I have in my library.
Andrew Grebneff can probably be very accurate with the Powell history.
Best Regards,
Leslie Allen Crnkovic
___________
Powell, A.W.B.
Note: (Shellfish of NZ 1937~1958, 1st-3rd ed) & (orig: Shellfish of NZ
1937/1946) Were taken from the bib page of the publications and appear to
conflict slightly.

1957 - Shells of New Zealand: An Illustrated Handbook, 3rd Ed Enlarged (orig:
Shellfish of NZ 1937/1946), Whitcombe & Tombs Pub, 202 pp, 36 pl, SB(L)

1976 - Shells of New Zealand 5th Rev Ed (Shellfish of NZ 1937~1958, 1st-3rd
ed), Whitcoullis Ltd, 154 pp, 45 pl, DJ HB(M)

1979 - New Zealand Mollusca: Marine Land & Freshwater Shells, Collins Pub, 500
pp, 82 pl, 120 fig, 2 map, DJ HB(L)
___________
Abbott, R. Tucker

1954 - American Seashells, 1st Ed, 4th Pr Mar 1958, Van Nostrand, 541 pp, 32pl,
100 fig, HB(L)

1974 - American Seashells: The Marine Mollusca of the Atlantic & Pacific Coast
of North America, 2nd Ed, Van Nostrand Reinhold, 663 pp, 24 cpl, 6405 id, 4000
+ il,
HB(L)