The holotype of Thatcheria mirabilis (Natural History Museum
registration number 1960154). The species was described in The
Proceedings of the Zoological Society London for 1877 by George
French Angas who said of it, 'This very remarkable shell, quite
unlike anything hitherto met with, was recently brought from
Japan by Mr Charles Thatcher'. Angas was at a loss to place it
in any known genus (G W Tryon remarked in 1881, 'That this shell
is a scalariform monstrosity cannot be doubted, but what may be
its normal form is not so readily ascertained'), with the result
that Mr Thatcher acquired immortality by having the new genus
named after him. The outer lip of the holotype was damaged and
has been rebuilt using papier maché. Although Angas did not
mention the damage, the repair is clearly visible in the
original plate. From 1877 right up until the 1930s no other
specimens were found until they began to be fished in Japanese
waters and became sought after by shell collectors, commanding
high prices until they bec