100 ESCHRICHT AND REINHARDT 



The hyoid of the right- whales differs from that of the rorquals by the posterior margin of its 

 middle portion being evenly excavated, instead of presenting two proceses with a notch between 

 them, almost as in the anterior margin. That of the Greenland whale seems to differ from 

 that of the Cape whale by the lateral cornua as well as the stylo-hyal bones becoming 

 thicker at their outer ends. During the growth of the animal the length of the lateral cornua 

 increases very considerably, comparatively speaking. Such is even to a greater extent the case 

 Avith the anterior cornua, by which means they at the same time appear to approach each other, 

 so that the notch between them becomes deeper and narrower. In the newborn Greenland whale 

 the ossified part of the middle portion was placed close to the anterior margin ; the anterior 

 cornua were still perfectly cartilaginous, the lateral cornua, on the other hand, only in their outer 

 conical ends ; the stylo-hyal bones were only ossified in their middle parts, both their ends being 

 still cartilaginous, and making together half the length of the bone. 



It seemed strange to us that even in our two full-grown specimens the stylo-hyal 

 bones, as well as the lateral cornua of the hyoid, were still found cartilaginous in their outer 

 ends {a!) ; they must therefore either not ossify at all or, at all events, at an exceedingly late 

 period. 



The larynx is an organ which has, quite exceptionally, already been accurately studied not 

 only in several rorquals, but has also been the object of a minute description in the case of 

 the Greenland whale, although it has not hitherto been examined in any other species of right- 

 whale. We here allude especially to the excellent memoir on this organ by Sandifort,^ who, 

 perhaps, would not have left anything for our further elucidation, still less for any emendations, 

 if he had not, as regards the Greenland whale, been limited to the examination of two small foetuses, 

 while we have had at our disposal the entire organ of the newborn individual and the cartilagi- 

 nous parts from the two full-grown ones. 



These cartilages of the larynx of the animal forty -seven feet and a half long are figured in Plate 

 VI, one sixth of the natural size. Fig. 1 shows the entire larynx from behind, or rather from the 

 upper surface, in its natural connection with the hyoid ; fig. 2, the cricoid and arytenoid cartilages 

 as well as the epiglottis from the right side ; fig, 3 shows the relation of the epiglottis to the 

 arytenoid cartilages, while the respiratory canals are closed, as seen from the inferior (ventral) 

 side ; fig. 4, the entire larynx, seen from the ventral surface ; fig. 5, the same seen from the 

 right side. 



In all the figures the letters have the following significations : 



e. The outer or ventral surface of the thyroid cartilage. 

 /. The anterior cornu of the same, 

 ^. The posterior cornu of the same. 



h. The ligament by which the anterior cornu of the thyroid cartilage is attached 

 to the hyoid (lie/ amentum tliyreo-liyoideiim). 



^ Nieuwe Verhand. d. Iste. Kl. van het Kon. Nederl. Instit. van Wetensch. te Amsterdam. 

 Derden Deals eerste Stuk. Amsterd. 1831, page 223. 



