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EXPLANATION OF THE PLATES. 



Plate X. Respiratory and Vocal Organs of the Blackbird, 

 Turdus Merula. 



FiG.l. Respiratory and Digestive Organs 

 of the Blaclchird exposed in situ. 



a, the bill. 



b, b, stylo-hyoideus. 



c, c, branches of hyoid bone- 



d, uro-hyal bone. 

 e,f, oesophagus. 

 g, stomach. 



h, i, j, duodenal fold of intestine. 

 k, anus. 



I, pectoral muscle. 

 m, heart. 



n, right lobe of the liver. 

 o, left lobe of liver. 

 p, p, lungs. 

 q, r, s, trachea. 

 t, bifurcation of trachea, 

 w, It, bronchi. 



V, V, contractor or sterno-tracheal mus- 

 cles. 

 tv, inferior laryngeal muscles. 



Fig. 2. 



Trachea of a Blackbird, ivith 

 its Muscles. 



a, b, trachea. 



b, b, cleido-tracheal muscles. 



c, c, lateral or contractor muscles. 



d, d, small slips. 



e, e, sterno-tracheal slips. 

 f,f, bronchi. 



Fig. 3. Tongue, Hyoid Bones, and 

 Larynx. 



a, tongue. 



b, b, horns of the hyoid bone. 



c, ligament. 



d, aperture of glottis. 



e, Trachea. 



f,f, cleido-thyroid muscles. 

 g, g, lateral muscles. 



Fig. 4. Bones of the Larynx with two 

 pairs of Muscles, the Arytenoid and 

 Thyro-cricoid. 



Fig. 5. Thyro arytenoid Muscles. 



Fig. 6. Thyro-cricoid Muscles. 



Fig. 7. Bifurcation of Trachea. 



Fig. 8. Last entire Ring of Trachea. 



Fig. 9. Lateral view of Inferior La- 

 ryngeal Muscles. 



a, anterior internal muscle. 



b, anterior external muscle, 

 e, posterior muscle. 



d, intermediate muscle. 



e, sterno-tracheal muscle. 



Fig. 10. Posterior view of Inferior 

 Larynx. 



