Authentication Ionic + Laravel

Ok, if I use

return this.http.get(this.api+'causes', options).map( res => res.json());

this is return Error:
Cannot find a differ supporting object '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays.

return a object

if I use this

return this.http.get(this.api+'causes' + options).map( res => res.json());

....causes[object%20Object]
any idea ?