397 



Column 4 gives the name of the species Solen vagina, because 



that species is found both living and fossil. 

 5 is left blank, because the names of those species only are 

 placed in this column which have no living analogues, 

 but are found in more than one period, or in more than 

 one formation of the same period. [Thus, in the next 

 line, Solen siliquarius has no living analogue, but it 

 occurs in two formations of the Miocene period, viz. at 

 Bordeaux and in Touraine.] 



6 shows that the living species of Solen vagina inhabits the 

 European Ocean and Mediterranean. 



, The two asterisks in the column of the Pliocene period show that the 

 species is found in two formations of that period, viz. in the Subapennine 

 hills arid the English crag. 



The asterisk in the column of the Miocene period shows that this spe- 

 cies is found in the basin of Vienna. 



The word Baden in the next column indicates that the species is also 

 found fossil in that localily. 



The column of the Eocene period is blank, because the shell has not 

 been found in any formation belonging to that period. 



The figures in the column of localities will be understood by what we 

 said above. In summing up these figures it will be found that they 

 amount to thirty-one, whereas it is stated, in the third column of the left- 

 hand page, that only nineteen fossil species have been found. The dis- 

 agreement arises from this that the same species occur in more than 

 one locality, and thus come to be counted more than once in the column 

 of localities. 



N.B. In some cases, before the totals of the species in the columns of 

 localities can tally with the figures in the third column, the species enu- 

 merated in the supplementary table of localities, p. 46, must be taken into 

 account. 



A note of interrogation added to the asterisk (*?) indicates a doubt 

 as to the correct identification of the shell, either because the shell is a 

 variety which has a somewhat distant analogy to the recognized type of 



