BALiENA. 25 



behind by a deep notch in upper border ; cavity opens 

 alono- inner surface by a moderately thick horizontal 

 border 8| inches above keel ; Eustachian end slightly 

 notched. Periotic relatively small, massive mastoid. 

 Auditory nerve canal distinct ; tympanic ossicles 

 present. Figure, p. 24, outer surface of tympanic. 



13. Tympano-periotic bones, fused, left, similar in character 



to No. 12. 



14. Tympanic bone, left. Dr Debuc's Collection. 



15. Tympanic bone, right, half of; the great thickness of the 



wall of the bulla is shown in the section. 



16. Tympanic bone, right, probably from a young B. iiiysti- 



cetiis. 



17. Tympanic bone, left, probably B. mysticetus. 



Dr R. Broom's Collection. 



18. Tympanic bone, right, probably B. mysticetus. 



19. Baleen plate, 47 inches long, 5 inches in greatest width at 



base, bristles slender. Colour slate grey, striped. 

 1888. Donor— Mr John M'Donald, s.s. " Maud." 



Turner Collection. 



20. Baleen. Nine small plates from the foetus of B. mysticetus, 



3^ inches long and | inch wide. Colour greyish white. 

 Wet preparation. Donor — Prof. P. J. van Beneden. 



21. Cast of cranial cavity; greatest width 18 inches. 



Cerebrum, cerebellum, rhinencephalon, medulla in- 

 dicated. From a skull in the Museum of the Royal 

 College of Surgeons, England. Purchased. 



22. Vertebral plates, four, of caudal vertebrae. 



[Nos. 23 to 30 are from the Collection made by 

 Professor Sir John Struthers, and were presented 

 by him. He has described the sternum in Journ. of 

 Anat. and Pliys., vol. xxix. p. 593, 1895 ; the carpus 

 in the same volume, p. 145 ; the rudimentary hind 

 limbs in vol. xv., 1881. The tibia in vol. xv. p. 160, 

 whale marked No. 11.] 



23. Sternum of Right Whale, an expanded oval plate, length 



27 inches, breadth 20 inches, articulating with the 

 first pair of ribs. 

 From Cumberland Sound, Davis Straits. 



24. Fore limb, articulated skeleton of right, young male ; 



carpal region modelled in wood. Length of humerus 

 15i inches, of radius 18 inches, of ulna 20 inches. 



