air-btjAddbe in notopterus bobneensis. 539 



9. EiDEwooD, W. G. — " The Air-bladder and Ear o£ British 

 Clupeoid Fishes." Journ. Auat. & Phys. vol. xxvi. 1892, 

 pp. 26-42. 



10. SoRENSEK, "W. — " Are the Extrinsic Muscles of the Aii-- 



bladder in some Siluridse, and the Elastic Spring- 

 apparatus of others, subordinate to Voluntary production 

 of Sounds P " " What is, according to our present know- 

 ledge, the Eunction of the Weberian Ossicles ? " Journ. 

 Anat. & Phys. vol. xxix., 1894-95. 



11. Stannius, H. — Handbuch der Zootomie der "Wirbelthiere. 



Die Eische. Berlin, 1854. 



12. Webeb, E. H. — "De aure et auditu Hominis et Animalium. 



Pars i., De aure Animalium Aquatilium." Lipsise, 1820. 



13. "Wiii&HT, E. Eamsat, McMukrich, J. P., Macullum, 



A. B., & McKenzie, T. — " Contributions to the Anatomy 

 of Amiurus." Toronto, 1884. Eeprinted from the Proc. 

 Canadian Institute (n. s.), vol. ii. 1884, p. 251. 



XI. EXPLANATION OF THE PLATES. 

 Plate 36. 



Fig. 1. Lateral view of the left branchial cavity, to show the relation of its 

 anterior CEecal extension to the left auditory cornu of the air-bladder. 

 The operculum and pectoral girdle have been removed. (Nat. size.) 



Fig. 2. View of the interior of a portion of the left caudal prolongation of the 

 air-bladder. The outer wall of the bladder has been partly removed 

 and partly reflei^ted above and below. A portion of the outer wall of 

 a ventral diverticulum has also been cut away in order to show one 

 of the ventral series of vacuities. (Nat. size.) 



Fig. 3. Lateral view of the anterior and abdominal portions of the air-bladder. 

 The outer wall of the left half of the bladder, except that portion of it 

 which is traversed by the obhque transverse groove between the sub- 

 spherical sac and the abdominal part of the organ, which has been left 

 as a narrow oblique strip, has been removed, so as to show the longi- 

 tudinal septum throughout its entire ength. The outer wall of the 

 left auditory caecum has been removed, and the oesophagus and ductus 

 pneumaticus laid open. (X 2.) 



Plate 37. 

 Fig. 4. Lateral view of the posterior portion of the right side of the skull. 



(X2.) 

 Fig. 5. View of the interior of the hinder part of the right half of the cranial 



cavity, as seen in a vertical longitudinal section of the skull. ( X 2.) 

 Fig. 6. Supero-lateral view of the posterior portion of the right side of the 



skull. (X2.) 



