Finding all of the children or descendants for a particular name

Search for the name in question e.g. Amphioxi

/names/search?query=Amphioxi

Extract the NameId from the response

Using an XPath query or something similar.

<NamesSearchResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Query>fullname:amphioxi</Query>
  <FilterQueries/>
  <SearchTime>115</SearchTime>
  <Total>1</Total>
  <Page>1</Page>
  <PageSize>10</PageSize>
  <MatchingTerms/>
  <FilterFields>...</FilterFields>
  <Results>
    <NameSearchResult>
      <Score>11.98188</Score>
      <Name>
        <NameId>aaa04924-2a3f-4d04-b327-3540f091b973</NameId>
        <Class>Scientific Name</Class>
        <FullName>Amphioxi</FullName>
        <FormattedFullName>&lt;em&gt;Amphioxi&lt;/em&gt;</FormattedFullName>
        <PartialName>Amphioxi</PartialName>

Get the list of children/descendants

/names?parentnameid=aaa04924-2a3f-4d04-b327-3540f091b973

This will return a paged list of all of the names that have Amphioxi as their direct parent.

The following url will get a list of all of the names that descend from Amphioxi.

/names?ancestornameid=aaa04924-2a3f-4d04-b327-3540f091b973