60 Annals of the South African Museum. 
the body of my work, but, to facilitate distinction, the reference 
number is printed in ordinary type before recent species, and in 
italics before those which have only been found, so far, in a fossil 
condition in South Africa. 
A list of authors and works consulted, with the abbreviations used, 
is given on p. 288. Owing to the great increase of recent literature 
on the subject, the list of references under each species has been 
lightened by the omission of all those of a purely ‘“ check-list” 
character, or of no actual value to the student. 
Many comparatively unimportant references to classification or 
locality only are also omitted, the authority quoted after each 
locality being, in the latter case, considered sufficient. 
I have also omitted many of the older references to European 
and American species, as the descriptions contained in them are 
of little value. 
The letters A. (anatomy), 
D. (description, external), 
fF’, (figure, external), 
LL. (locality), 
NN. (note), 
fi. (vadula), 
are appended respectively to each reference to denote the class of 
information it contains. 
With regard to Férussac’s Tabl. Syst. des Moll., part iii., of which 
there were two editions in the same year, with different pagination, 
the alternative pages are given. 
The species described and figured by Sturany in Siidafr. L.- und 
S.-W.-Moll., November, 1898, were first published by him in a 
‘Preliminary Note’ in the Anz. kais. Akad. Wiss. Wien, in June 
of the same year. I have not, in this instance, quoted the earlier 
reference, except in the case of Chondrocyclus isipingdensis, where 
priority of nomenclature is involved. 
The present work is intended, primarily, to be of as much use as 
possible to students in South Africa. This accounts for my having 
appended full references to Genera and the higher divisions, many 
of which I have found it quite impossible to trace in any library 
in that country; and also for the addition of as many localities 
for each species as I have been able to gather; but it has been, 
naturally, quite impossible to verify the correctness of all of the 
latter. Many of the older specific names have been misapplied, at 
yarious times, to other species, while many recently described shells 
