al 
WINDOW GROUPS 55 
Next to be visited are the silver sharks or Chimaeroids, which are 
exhibited by the side of the lamprey case. They are now known to 
be highly modified sharks: their scales have failed to develop, and their 
heavy ‘‘teeth”’ appear to represent many teeth fused together. These 
fishes are now very rare and, with few exceptions, occur in the deep sea. 
The present models show the characteristic forms. 
The adjacent case pictures the three types of surviving lungfishes, 
and the models are arranged to indicate the life habits of these interest- 
ing forms. Thus they are shown going to the surface of 
the water to breathe; and their poses indicate that they 
use their paired fins just as a salamander uses its arms and legs. In 
fact, there is reason to believe that the land-living vertebrates are 
descended from forms closely related to lungfishes. One sees in this case 
also a‘‘cocoon,’’ in which the African lungfish passes the months when the 
streams are dried up and during which time it breathes only by its lungs. 
Returning again to the cases of sharks, one sees on a panel above 
them two huge sturgeons and two large garpikes. These are examples 
of the group known as Ganoids—fishes that represent, as it were, 
a halfway station between lungfishes and sharks on the one hand, and 
the great tribe of bony fishes on the other—such as perches, basses, cod, 
ete. <A further glimpse of the Ganoids may now be had by viewing the 
spoonbill sturgeon (paddlefish) group, on the side opposite. In this 
group a number of these eccentric fishes are shown side by side with gar- 
pikes and other characteristic forms from the lower Mississippi. This 
group was secured through the Dodge Fund. In the window are groups 
showing the shovel-nosed sturgeon, and the spawning 
habits of the bowfin and of the slender-nosed garpike,— 
allGanoids. See page 54. 
Passing now through the door leading to the Bird Hall, we are con- 
fronted by a case containing additional examples of the Ganoids. Here 
one sees garpikes, sturgeons, the mudfish (Amia), together with the 
African Bichir, a curious Ganoid encased in bony scales and retain- 
ing structures which bring it close to the ancestral sharks. 
The remaining cases in the center of the bird hall give characteristic 
examples of the various groups of modern “bony fishes,” 
or Teleosts. There are fourteen cases of them in all, 
but they offer little space in which to illustrate the 10,500 species. 
For these are the fishes which are dominant in the present age, con- 
tributing over nine-tenths of all existing forms and including nearly 
all food and game fishes such as bass, cod, eel and herring. 
The cases should be examined in the order in which they are arranged; 
and one may pass in review the catfishes, carps, eels, trout, salmon, 
Lungfish 
Window 
Groups 
Teleosts 

