20 FIE LD MUSEUM OF NATURAL HISTORY 
The portion of the skeleton shown is thirty feet long and 
stands fifteen feet above the base. In life the neck was equal in 
length to the portion of the tail here exhibited. The tail was at 
least one-half longer. From this it may be seen that the entire 
length of the animal would have been about sixty feet, or eight 
feet longer than the hall in which it is exhibited. 
The various series of vertebrae, scapulae, pelves, sacra, leg 
bones, and feet exhibited in the adjoining wall cases represent a 
number of other types of Dinosaurs, most of which are smaller 
than the central figure. Among these are represented the fol- 
lowing genera: Morosaurus, Camarasaurus, Brachiosaurus, and 
Creosaurus. 
At the end of the hall may be seen a complete fore leg and 
shoulder-blade of the medium-sized dinosaur, Morosaurus. Two 
large leg bones of Brachiosaurus shown are the largest known to 
science. They measure six feet eight inches in length, and the 
thigh-bone weighs seven hundred pounds. The unusual length 
of the humerus in comparison with the femur shows that the 
animal to which they belonged must have stood higher at the 
shoulders than at the hips. 
Halls 36, 59, 60, and 61. 
These halls are devoted to fossils of the remaining geological 
periods, from the Jurassic onward. Owing to the size of many 
of the specimens it has not been possible to place them in exact 
geological order, but groups are shown together as far as possi- 
ble. 
Jurassic Period. — Gouiospongia, Cfiewiidiastrum, Retispongia, 
Craticularia, Hyalotragos and Pyrgochonia illustrate the various 
forms of Jurassic sponges. Rhizostomites shows the form of the 
gastral cavity of a jelly-fish. 
Two types of crinoids are shown. The first, illustrated by 
Pentacrinus, had a comparatively small body attached by a 
long stem and a large number of long, many-branching arms. 
The other type, illustrated by Antedon, was a stemless, free- 
swimming form with only a few short arms. 
Ophiura and Asterias are typical starfishes. 
Jurassic sea-urchins are of two types and a representative 
series of each is shown. Cidaris, Heniicidaris, Acrocidaris, Dia- 
dema, and Stomechinus belong to the type having the shell di- 
