Figure 2

Oral cavity and brain morphology of M. conophoros and C. virginalis. (A) The dorsal oral cavity of the pit-digger C. virginalis is comparatively simple and lacks a distinct palatal organ. (B) The dorsal oral cavity of the castle-builder M. conophoros displays a more convoluted structure and caudal palatal organ labeled ‘PO’. (C) Photograph of in situ caudal brain structures of C. virginalis. The approximate location of the vagal lobe is outlined and labeled ‘VL’ and the cerebellum is labeled ‘Cblm’. (D) Photograph of in situ caudal brain structures of M. conophoros. As in (C) the approximate location of the vagal lobe is outlined and labeled ‘VL’ and the cerebellum is labeled ‘Cblm’.