ON THE CETACEAN LARYNX. ( 
the cricoid by a synovial capsulated joint. The anterior horn is a long, laterally compressed and pointed 
structure in the upper half of its extent, but in the lower half of its surface is thickened and convex from 
side to side. It is connected to the arytenoid body by fibrous tissue, so that it is freely moveable on it as 
is the case in Platanista. The posterior horn is a downward prolongation of the anterior, and is a rounded 
bar of cartilage, and terminates abruptly in a flattened end at the lower portion of the penultimate sixth of 
the arytenoid body, where it is capped by two small cartilages applied to each other laterally, succeeded by 
another cartilage which is wedged in between them and the last sixth of the arytenoids, and curving for- 
wards overlies them. A great part of the attachment of the aryteno-epiglottidean ligament takes place from 
the outer border of these cartilages” (loc. cit. p. 387). 
Thus so far as this description goes, the muscles not being described, we have 
here the exact counterpart of the foetal larynx of Gilobiocephalus. We have, that 
is to say, a distinct arytenoid and supra-arytenoid ; and we have, segmented off 
from the inferior extremity of the latter, in close relation with the aryteno-epiglotti- 
dean ligament, a separate cartilage, comparable to the Cartilage of WRISBERG. 
Fig. 12. Larynx or Puatanista. Fig. 13. Larynx or ORCELLA. 
Posterior view. (After ANDERSON.) 
To conclude, the so-called arytenoid cartilage of the Delphinoid Whales 
originates in two parts, of which one receives the whole of the arytenoid muscles, 
and is therefore proved to be the true arytenoid: the other may be called the 
supra-arytenoid. This supra-arytenoid itself tends to divide into two parts. Its 
inferior or ventral extremity becomes separated off, apparently owing to its implica- 
tion in the great aryteno-epiglottidean ligament: it may therefore be considered 
homologous with the Cartilage of Wrispere of human anatomy. The remaining 
superior and much larger portion of the supra-arytenoid is thus homologous with 
the Cartilage of SANTORINI. 
The young stages of the larynx in the Balaenoidea are not known. In all 
probability, in them also the arytenoid is of double origin, its supra-arytenoid horn 
being relatively much smaller, and its basal or true arytenoid part being remarkably 
prolonged along the superior border of the cricoid. 
