22 ON THE SKULL IN THE WOODPECKERS AND WRYNECKS- 



Fig. 5. 1st of a series of vertically transverse sections of face of Yunx torquilla, x 8 diameters. 



Fig. 6. 2nd section of ditto, x 8 diameters. 



Fig. 7. 3rd section of ditto, x 8 diameters. 



Fig. 8. 4th section of ditto, x 8 diameters. 



Fig. 9. 5th section of ditto, x 8 diameters. 



Fig. 10. 6th section of ditto, x 8 diameters. 



Fig. 11. Part of same, x 24 diameters. 



Plate V. 



Fig. 1. Side view of skull of Gecinus viridis. x 2 diameters. 



Fig. 2. Fore view of ethmoid of ditto, x 2 diameters. 



Fig. 3. Palate of Picumnus minutus (from below), x 10 diameters. 



Fig. 4. Part of ditto (from above), x 10 diameters. 



Fig. 5. Part of dito (side view) . x 10 diameters. 



Fig. 6. Side view of septum nasi of Picumnus minutus. x 10 diameters. 



Fig. 7. Diagram of visceral arches and sense-capsules in the embryo of an aerial bird at the middle of 

 incubation : — ol, nasal sac ; e, eye ; au, auditory sac ; tr, trabecula ; p.n, prenasal ; c. tr, tra- 

 becular cornu ; pa, palatal ; pg, pterygoid ; q, quadratum ; mk, Meckel's cartilage ; st, stipes ; 

 5, 5th nerve; s.st, suprastapedial ; e.st, extrastapedial ; i.st, infrastapedial ; st.h, stylohyal ; 

 c.hy, ceratohyal; bh, basihyal; uh, urohyal; br. 1, 1st branchial. 



