Fig. 1.

Chondrocranium of Ptychoglossus bicolor at stages 31 and 32–33. Stage 31: (A) dorsal view, (B) lateral view. Stage 32–33: (C) dorsal view, (D) lateral view. Abbreviations: acc, acrochordal cartilage; asp, ascending process of pterygoquadrate; bf, basicranial fenestra; bpl, basal plate; bpt, basipterygoid process; ca, columella auris; fhn, hypoglossal foramen; fm, fissura metotica; Mc, Meckel's cartilage; n, notochord; ns, nasal septum; oa, occipital arch; oc, otic capsule; pm, pila metoptica; ps, planum supraseptale; ptc, parietotectal cartilage; q, quadrate; t, trabecula; tc, trabecula communis; tp, trabecular process of acrochordal cartilage. Scale bar: 0.5 mm.