Web API picklist code and name

I'm using Microsoft Dynamics CRM Online 2016 (8.1.0.526). And querying/importing data via OData connector using Web API web services.

I use the following URL to get the list of entities,

https://[Organisation].api.crm4.dynamics.com/api/data/v8.1/

and then I select contacts in the list of entities. When I look at the data I can only seecode (see below screenshot) how do I get the name?

e.g. how can I retrieve new_countryoforiginname column using Web API call. I dont see any corresponding entity that is equivalent to StringMap table. How are the exposed? 

Subash.S