DEPARTMENT OE ZOOLOGY 127 
Achatina. Most of the species live in Africa, where they remain 
in trees, descending to lay their eggs. Some of the eggs are 
exhibited. 
Case 29. — Stenogyridce continued; Pupidce; Bulimulidce; 
Helicidce. 
Cases 30, 31, 32 and 33. — Helicidce (Air-breathers), a large 
family containing over 6,500 species. Many of the most attrac- 
tive specimens in these cases are from the Philippine Islands. 
Some species of Bulimus reach a length of six inches. They 
lay large eggs, which resemble those of birds; some of these 
are shown. 
Case 34. — Testacellidce ; Limacidce (Slugs), a few families of 
Pteropoda and the Cephalopoda, a class which includes the Nau- 
tilus, the Squids, the Octopus and Argonauts. A few of the 
soft Cephalopoda are represented by means of glass models. A 
model of the Giant Squid of the coast of New Foundland and 
the Giant Octopus of the Pacific Coast of the United States are 
suspended overhead in Hall 24. 
Hall 19. 
MAMMALS. 
Case 1. — Four representatives of the lower sub-class of Mam- 
mals, the Prototheria. Of these the most interesting is the Aus- 
tralian Duck-bill (Ornithorhynchus) y so called on account of its 
duck-like beak. It is aquatic in its habits and swims with facil- 
ity. Although a true mammal, the remarkable fact has been 
discovered that it lays eggs instead of producing living young. 
The Echidnas, or Spiny Ant-eaters, are inhabitants of New 
Guinea, Tasmania and Australia. 
This case also contains members of the second sub-class of 
Mammals, the Metatheria, order Marsupialia. These comprise 
the Phalangers, the Bandicoots, the Kangaroos, the Dasyures, 
all inhabitants of Australia, Tasmania and New Guinea, and the 
Opossums, dwellers in the Americas. They present many 
strange and interesting forms of life. The Phalangers usually 
live in trees and have prehensile tails. Some species subsist on 
vegetation, others on insects. The “flying phalangers’’ resem- 
ble our flying squirrels, in having a fold of skin which acts as a 
parachute. The Bandicoots (Perameles) burrow in the earth 
