Mapping List- Hibernate

CLASS:
 
public class Regra
{
    // ...
    Long id;
    private ArrayList <Clausula> antecedentes;
    // constructor, gets, sets ...
}
 
MAPPING:
 
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 
<hibernate-mapping>
    <class
        name="especialista.regra.Regra"
        table="REGRAS">
        <id
            name="id"
            column="CLAUSULA_ID">
            <generator class="increment"/>
        </id>
        <list name="antecedentes" table="ANTECEDENTES_REGRA" cascade="all">
            <key column="id"/>
            <list-index column="POSITION"/>
            <element type="especialista.regra.Clausula" column="ANTECEDENTE"/>
        </list>
    </class>    
</hibernate-mapping>
 
EXCEPTION:
 
Exception in thread "main" org.hibernate.PropertyAccessException: IllegalArgumentException occurred while calling setter of especialista.regra.Regra.antecedentes
        at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:104)
        at org.hibernate.tuple.entity.AbstractEntityTuplizer.setPropertyValues(AbstractEntityTuplizer.java:337)
        at org.hibernate.tuple.entity.PojoEntityTuplizer.setPropertyValues(PojoEntityTuplizer.java:200)
        at org.hibernate.persister.entity.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:3566)
        at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:277)
        at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
        at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:121)
        at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
        at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
        at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
        at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
        at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
        at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
        at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
        at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
        at persistencia.dao.HibernateText.main(HibernateText.java:28)
Caused by: java.lang.IllegalArgumentException: argument type mismatch
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:42)
        ... 15 more
Java Result: 1