16 
single black strip separates Species of the same genus ; a red strip 
Genera under the same family ; a white strip Families under the 
same order ; two white strips separate Orders, and two black ones 
Classes or higher divisions. Green tickets on, or by the side of a 
specimen, indicate one that has been used in the original descrip- 
tion of the species (type), or has been described and figured in 
some published work on the subject, to illustrate a previously 
described species (figured specimen). 
LIFE RECORDS. 
The times of the first appearance, in geological history, of the 
different groups of animals and plants, as well as their increase 
and decrease during the several ages, is partially represented by 
the following diagrams, taken from Dana's Manual. The first 
diagram gives a general view of the Animal and Vegetable king- 
doms, from their first appearance to the present time ; the next 
three give the origin, development and disappearance of Animal 
life during Paheozoic time, and the last, that of the Vertebrate 
kingdom from the close of Palaeozoic time to the advent of Man. 
The initial point of the shaded area, representing any form of 
life, indicates its first appearance in the geological record at that 
period. The breadth of the area shows its greater or less devel- 
opment during the successive epochs or ages while it existed. The 
ages and periods being marked at the top, except in Fig. 3, where 
they are on the margin. 
rig - 3 ANIMALS. PLANTS. 
Age of Man, i 
or Quaternary, j 
Age of Mammals, ( 
or Tertiary. f 
Age of Reptiles, 
or Secondary. 
Carboniferous Age. 
Age of Pishes, 
or Devonian. 
Age of Invertebra- I 
tes, or Silurian. ( 
Archasan Time. 
