BAL^NOPTERA. 39 



51. Eyeball, anterior segment of a transverse section of a 



large Rorqual, showing the great thickness of the 

 sclerotic and the sections of two tubes through which 

 the long ciliary arteries pass. 



52. Eyeball, posterior segment of the same Rorqual, showing 



the foramina of transmission of the short ciliary 

 arteries and nerves, and a transverse section through 

 the optic nerve. 



58. Eyeball of the Rorqual, B. musculiis. An antero-posterior 

 section has been made through the axis of the optic 

 nerve ; the great thickness of the posterior part of the 

 sclerotic coat is shown. 



54. Eyeball. Antero - posterior section through sclerotic, 



cornea, iris, and choroid. The pigment layer has been 

 removed from the choroid to show its hbro-vascular 

 layer. 



55. Eyelids of a small Rorqual with the palpebral fissure. 



56. Penis. Transverse section through the penis of a large 



Rorqual, probably B. miLsculus ; transverse diameter 

 9 J inches, dorso- ventral diameter 8 inches. The 

 corpora cavernosa are blended ; the fibrous coat is 

 2i inches thick ; the erectile cavernous part is 7 inches 

 in transverse diameter. The corpus spongiosum 

 projects on the ventral surface, and the transverse 

 diameter of the urethra is 1;^ inch. 



57. Pennella balsenopterse, a crustacean parasitic on B. mus- 



cuhis, obtained September 1903. Described by Sir 

 Wm. Turner, Trans. Roy. Soc. Edin., vol. xli., 1905. 

 See Pathological Catalogue of the University Museum, 

 section on parasites, p. 397. 



Donor — Mr Christopher Castberg. 



(2) Bal.enoptera sibbaldi. (Bpt. s.) 

 (Sibbald's Rorqiial, Bh;e Whale.) 



Balsena tripinnis (|U8e maxillam inferiorein rotundam et 



superiore multo latiorem habuit, R. Sibbald, Phalaino- 



logia nova, Edinburgh, 1692. 

 Balsena maximus borealis, Knox, Cat. Mus., 1838. 

 Pliysalus sibbaldii, Gray, P.Z.S., 1847. 

 Baltenoptera sibbaldii. Flower, Van Beneden, Turner, and 



others. 

 Bala^noptera musculus, sulphur bottom, True, Smithsonian 



Contributions, vol. xxxiii., 1904. 



