\hbox{
  \hfil
  \picture{../photos/2019-12-13-3.jpg}{An antlion in the inter-trial holding containers with native sand}{3.5in}
  \hfil
  \picture{../photos/2019-10-18-2.jpg}{The full, original hosting container for antlions (32x33), with significant wandering}{3.5in}
  \hfil
  \picture{../photos/c.jpg}{All of the antlion holding containers in the corner}{3.5in}
}
