Error in package

[ency@portatile-gio-antegos Test]$ javac -cp '.:Animali.jar' Main.java
[ency@portatile-gio-antegos Test]$ java Main
Inserisci [s] per uno squalo o [c] per un cane: c
Aggiungo un cane...
Exception in thread "main" java.lang.NoClassDefFoundError: Animali/Dog
	at Main.main(Main.java:26)
Caused by: java.lang.ClassNotFoundException: Animali.Dog
	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
	... 1 more
[ency@portatile-gio-antegos Test]$ java Main
Inserisci [s] per uno squalo o [c] per un cane: s
Aggiungo uno squalo...
Exception in thread "main" java.lang.NoClassDefFoundError: Animali/Shark
	at Main.main(Main.java:21)
Caused by: java.lang.ClassNotFoundException: Animali.Shark
	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
	... 1 more
[ency@portatile-gio-antegos Test]$