PREFACE. Vv 
panion to it, should be regarded as an integral portion and 
Apprenprx. It was in following up this design that our first 
plate was numbered 9, the sequence to the eighth and final 
supplementary plate of that useful iconography: in every 
other respect this volume is independent of it. 
The terms “ posterior” and “anterior” have been used 
in accordance with the ideas of the older conchologists, and 
conversely to their modern signification. This is to be 
regretted, and has only been continued to the end, in order 
that the phraseology should harmonise throughout. 
Allusion has already been made to the long period which 
has elapsed since the commencement of these pages. It 
behoves us now to furnish the several dates of their publica- 
tion. Sheets B, c, were separately issued at the close of 
1842,* and conjointly (p. 1 to 144) with the seven suc- 
ceeding ones in the early part of 1843, almost simul- 
taneously with plates 9 to 13, and their explanatory text. 
Sheets i to s (p. 145 to 272) appeared at the close of the 
same year, and were followed, about a twelvemonth after, by 
plates 14, 15,16; and at a long interval (two years or there- 
abouts) by plates 17, 18, 19. Sheet rT (p. 273 to 288), 
although it has been printed for many years, now makes its 
* Under the title of ‘ Lamarck’s Species of Shells.’ The letter- 
press was accompanied by two plates, the figures in which had been 
transferred to stone from our first five plates (on which they had 
been somewhat promiscuously engraved, having been designed for 
lithographic transposition) and the earlier engravings of the ‘ Index 
Testaceologicus.’ The publisher, dissatisfied with their execution, 
discontinued the work, which should contain 3 plates and 224 
pages. 
