I()SS/L AQCMi'll M 101 



In tlic first al('()\(> to the left. 1)\- tlic window, is a " fossil 

 Fossil ., . ... , '. I I 1- 4 1 I- * 



. . aciuaniun in which a niunhcr ol models ol these earhest 



Aquarium . ' 



fislies are arran,i!;e(l in a «2;roui). as th()U«;li alive in the sea. 



In the next alcove are tlie (>arl\- fossil sharks which sii|)ersede(l tiie 



tribe of j)late(l fishes just mentioned. These sharks had soft skeletons. 



c, , sim])le fins and a number of other i)rimitive features which 



Sharks ' ' 



lead to the beli(>f that all of tlie hi<>;her Hslies, and the lii<iher 

 back-boncul animals therefore as well, weri^ descended from them, their 

 simpler structures becoming- more comi)licate(l in many directions. In 

 one of the early sharks her(^ exhibited, impressions of .soft parts such as 

 muscles and gill filanu^nts have been i)reserved. 



In the third alcove api)ear rare fossils of silver sharks or ChimaToids, 

 _, . . , which appear to havel)een tleveloped from a primitive race 



of sharks. Curiously enough fossil egg capsules of these 

 forms are sometimes preserved, and examples are here present. In neigh- 

 boring cases are shown ancient lungfishes and ganoids — groups from 

 which all land-living quadrupeds are believed to l^e descended. 



In the fourth alcove are shown the ganoid fishes Avhich dominated the 

 ^ . , waters during the Age of Reptiles. They were of many 



kinds and sizes, most of them with lozenge-shaped scales 

 of bone, with enamelled surface. One of the few^ survivors iA7uia) of this 

 ancient group is here shown living (in a window aquarium), to give the 

 visitor a clearer idea of the fishes of the "Middle Ages" of the world. 



In the fifth alcove are the petrified fishes of the Age of Mammals. By 

 -, - this time nearly all of the primitive fishes, like sharks, lung- 



fishes and ganoids, had become extinct; and the common 

 forms were bony-fishes, or teleosts, closely related to our herrings, 

 perches, mackerels and daces. 

 [Return to the South Pavilion or Hall of Mastodoiis and Mammoths.] 



SOUTH CENTRAL WING 

 Geology and Invertebrate Paleontology 



Turning northward at the center of the Quaternary Hall containing 

 the mastodons and mammoths, the visitor enters the South Central Wing 

 of the building and is in the Hall of Geology and Invertebrate Palaeon- 

 tology. Owing to important changes in the rearrangement of this hall, 

 but a portion of the collections are at present on exhibition, though all 

 are available for study. At the north end is a reproduction of a portion 

 of the beautiful cave in the Copper Queen Mine at Bisbee, Arizona, 

 while opposite, an elaborate model of the mine is being assembled. 



At the entrance of the hall is that portion of the collections of meteor- 

 ites which includes the smaller specimens. Nearby the visitor will see an 

 exhibit illustrating some of the results of an expedition which the 



