II I \ i)(n\ (,h'(}( rs ., , 



Next \\t Im- \isit('(l art' the silxcr sliai-ks of ('/il/fKicnn'ds, whicli aic 

 exhibited l)y tlic side of tlic lam|)i"(\N' case. They aic now known 1o 

 he hi«»;hly modified sharks: their scales have t'aih'd to develoj). and tlieii- 

 heavy "teetli" appear to rei)reseut many teeth fused to«!;ether. These 

 fislies are now very rare and. witli few exceptions, occur in the deej) sea. 

 The ])resent models show the characteristic forms. 



The adjacent ca.se ])ictures the three types of sur\i\iu^ luu^fishes. 



and the models are arranged to indicate the life habits of these interest- 



^ ^- iiii^ forms. Thus thev are shown ^oin^' to the surface of 



Lungfish ■ 1 ' 1 1 • I- I , 



tiie water to breatlie; and tlieir poses mcucate that they 



use their ])aired fins just as a salamander uses its arms and legs. In 

 fact, there is rea.>^on 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 whicli time it breathes only 

 by its lungs. 



Returning again to the cases of sharks, one sees on a panel above 

 them tw^o huge sturgeons and two large gar pikes. 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, 

 etc. 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 characteri.stic 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 slend(T-nosed sarpike, — 



all Ganoids. 

 Passing now through the door leading to tlie Bird Hall, we are con- 

 fronted by a case containing additional examples of the Ganoids. Here 

 one sees garpikes, sturgeons, the mudfish {Aniia), together with 

 the African Bichir, a curious Ganoid encased in bon}' 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- 

 tril)uting 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 ; 



