roll call vs subfamily

roll call

noun
  • The subset of those members of a specific group who are present or available out of the full set of all the members of said group. 

  • The time of day fixed for such an event. 

  • Such an event in a legislative body in order to determine if a quorum exists. 

subfamily

noun
  • A secondary or subordinate grouping. 

  • A taxonomic category ranking between a family and a genus; formerly called a tribe 

How often have the words roll call and subfamily occurred in a corpus of books? (source: Google Ngram Viewer )