ON THE CETACEAN LARYNX. 5 
upon the upper border of the cricoid. The body of the thyroid is broad in the 
middle, very narrow laterally: the anterior cornu is short and blunt, the posterior 
narrow and long. The anterior extremity of the epiglottis overlaps but is closely 
united by membrane to the body of the hyoid. 
In a foetus of Lagenorhynchus albirostris, about two feet in length, the adult 
condition is more nearly approached. The arytenoids are now much enlarged, and 
elongated in an antero-posterior direction, lying, as shown in the annexed figure, 
hon the superior border of the long decurved ventral horn of the cricoid. The 
Fig. 10. Larynx or rorran Lagenoruyncuus (natural size), 
arytenoid is enfolded by the supra-arytenoid, but no actual fusion has taken place. 
The separate nodule at the ventral extremity of the supra-arytenoid is very 
distinct. The anterior horn of the thyroid is rudimentary, the posterior very long : 
there is no thyroid foramen. 
In a nearly adult Delphinus delphis (7 feet long), whose larynx is very like 
that of Lagenorhynchus, the supra-arytenoid is seen to have increased in size, when 
compared with the former figure, relatively to the arytenoid and to the cricoid: 
the arytenoid is still separate, though very intimately connected with the supra- 
arytenoid; and the nodule at the ventral extremity of the supra-arytenoid is 
distinct, and of irregular elongated form. The epiglottis has greatly increased in 
size and massiveness: the area of its attachment to the body of the thyroid has 
diminished, and its posterior angles embrace the arytenoids. 
In a specimen of Globiocephalus, about 12 feet long, the anienel is still 
separate from its adjacent cartilages. The supra-arytenoid, at its original point of 
articulation with the arytenoid, articulates with the latter by a smooth cartilaginous 
facet; beyond, that is to say ventral to that point, it slightly overlaps, and no 
special surface of articulation is developed: but such a definite articular surface is 
again present where the arytenoid meets the terminal nodules of the supra- 
arytenoid. In older specimens of Globiocephalus the whole are fused. 
