INTRODUCTION. 9 
deprived these annotations of the freshness of novelty. Indeed 
a small portion of them (the turreted Turbines) has already 
been published (May 19, 1849), yet, as twelve copies only were 
printed, it may reasonably be presumed that the majority of my 
readers have not perused it. The advantage of possessing in 
one work the conclusions arrived at respecting all the Linnean 
shells collectively can scarcely fail to be appreciated by the sci- 
entific student: the exact reprint, too, of the ‘ Vermes 'Testacea,’ 
with the double paging, which will enable him to find the many 
references of authors to the ‘Systema’ and ‘ Mantissa’ with 
the same facility as in the original twelfth edition, and thus to 
dispense with the purchase of the five volumes from which it is 
extracted, must prove useful to that section of naturalists which 
devotes its exclusive attention to Conchology. 
