1901.] 



LARYNX OP CERTAIN WHALES. 



299 



Macalister. — " On some Points in the Anatomy of Qlohiocephalus 



svineval." Proc. Zool. Soc. 1867, p. 477. 

 Pebrin. — " Notes on the Anatomy of Balcenoptera rostrata." Proc. 



Zool. Soc. 1870, p. 805. 

 Turner. — " Anatomy of Mesoplodon bidens.'" Journ. Anat. & 



Physiol. XX. 1886. 



EXPLANATION OP THE PLATES. 



Tlie letters used have the following significance ; in the case of muscles, the 

 letters refer both to the muscles and their attachments. 



Transverse and circular 

 muscles of the sublaryu- 



A. Arytenoid cartilage. 



a. Upper plate of epiglottis. 

 A.ep. Aryteno-epiglottid muscle. 



A.e23.f. Aryteno-epiglottid fold. 

 A.jjiii. Processus muscularis, or 

 base of arytenoid cartilage. 

 Ar. Arytenoid body. 

 A.w. Supra-arytenoid region of 

 arytenoid cartilage. 



b. Lower half of epiglottis. 

 C. Cricoid cartilage. 



C.a?: (Posterior^ crico-arytenoid 

 muscle. 

 Car. I. Lateral crico-arytenoid 

 muscle. 

 C.c. Veutro-posterior coruu of 



cricoid cartilage. 

 C.t. Crico-thyroid muscle. 

 E. Epiglottid cartilage. 

 Ep. Epiglottis. 

 Ep.c. Cushion or ridge of epi- 

 glottis or its cartilage. 

 /. Fossa ; on external face of 

 arytenoid cartilage. 

 /.a. Articular iacet for arytenoid 



cartilage. 

 J'.c. Articular facet for cricoid 



cartilage. 

 f.t. Articular facet for posterior 

 cornu of thyroid cartilage. 

 ffr. Groove in epiglottid cartilage. 

 H.ep. Hyo-epiglottid muscle. 

 I.ar. Inter-arytenoid muscle. 

 L. Cavity of larynx. 

 m. Median dorsal prominence 

 of cricoid (Cogia). 

 mus.p. Muscular wall of sublaryn- 

 geal pouch. 



geal pouch. 

 0. Glottis : entrance to larynx 

 from SLiblaryngeal pouch. 

 (E. CEsophagus. 

 ■p. Processus vocalis of aryte- 

 noid cartilage. 

 Pal. Palate. 

 Ph. Pharynx. 

 Ph.fl. Floor of pharynx. . 

 Ph.vmn. Muscular wall of pharynx. 

 P.n. Posterior nares. 



r. Accessory crico-thyroid 

 muscle {Balcenoptera). 

 r. Eidge on cricoid cartilage 

 (Cogia). 

 S.ep. Subepiglottid cartilage. 

 S.l.p. Sublaryngeal pouch. 

 S.t. Sterno-thyroid muscle. 

 T, Thyroid cartilage, 

 y*. Posterior cornu of thyroid 



cartilage. 

 T.ar. Thyro-arytenoid muscle. 

 T.c. Thyro-cricoid muscle in 

 Bal<snoptera. 

 T.ep. Thyro-epiglottid muscle. 

 T.h. Thyro-hyoid muscle. 



tr. Trachea, or tracheal rings. 

 T.t. Tubercle or ridge on the 

 anterior margin (= ante- 

 rior cornu) of thyroid. 

 JV. Tendon, passing froia body 

 to posterior cornu of thy- 

 roid (in Cogia). 

 X. Muscle of vtneertain homo- 

 logy. 



Plate XXV. 



Fig. I. Balwnoptera. Ventral view of entire larynx, as seen after the removal 

 of the hyoid and the wall of the pharynx. Some of the muscles 

 have been removed from the right side of the figure, so as to show the 

 shape and relations of the cai^tilages. 



The right longitudinal muscle (thyro-cricoid) of the sublaryngeal 

 pouch has been cut away so as to exhibit the deeper circular 

 muscles (M.). 



Fig. 1 a. The median region of the above figure, after the removal of the whole 

 of the thryo-cricoid muscle, showing now the outline of the sub- 

 laryngeal pouch. The area of attachment of the longitudinal muscle 

 is indicated by the dotted lines. 



