- 1. Frog (Rana) embryology: neurula stage t.s. Lieder_4496f
- 2. Frog, neurula, t.s. showing primordium of notochord, entoderm with primary intestinal cavity Lieder_8304f
- 3. Rana embryology: frog, neurula t.s. Lieder_Am294f
- 4. Frog, early neurula, t.s. shows the neural plate Lieder_Em609f
- 5. Frog, medium neurula, t.s. shows the neural groove Lieder_Em610f
- 6. Frog, late neurula with neural tube, t.s. through the intestinal region Lieder_Em611f
- 7. Frog, late neurula with neural tube, t.s. through the frontal region Lieder_Em612f