ON THE GREENLAND RIGHT- WHALE. 103- 



to the description of its separate parts given by Sandifort. Of emendations, properly so called, 

 we have only one to make, namely, that the two descending cornua {g — g) of the thyroid are 

 really, in the Greenland whale, as in the rorquals, firmly united as one continuous cartilaginous 

 mass with the plate. That Sandifort should have believed that he found an articulation between 

 them must, no doubt, only be ascribed to these brittle parts having been, accidentally broken 

 in the tender foetuses. The rest of our observations will be limited to some unessential difi'er- 

 ences of form, very conspicuous in our more developed specimens. 



The plate of the thyroid we found much thickened along the mesial line in the form of a 

 ridge, which, however, towards the posterior margin was turned towards the left side, so that the 

 cartilage in this place became rather unsymmetrical. On the posterior margin of the thyroid 

 the notch was further found to be considerably more obtuse than represented by Sandifort, and 

 the two posterior cornua were not so very little inflected in an outward direction. But his 

 statement that the two great foramina on the thyroid of the rorquals are quite wanting in the 

 Greenland whale we found fully confirmed. As to the arytenoid cartilages, we shall only point 

 out the fact that their anterior cornua in the full-grown individuals presented a far more 

 beautiful form than in the imperfectly developed foetuses examined by him. While in situ they 

 resemble, especially when seen from behind (fig, 1, n — -p — ri), two swans' necks inclined towards 

 each other. The epiglottis Qc), too, has a much more elegant form than was observed in 

 the foetuses. It is provided with a longitudinal ridge on its posterior surface (fig. 3). By a 

 special ligament (figs. 4 and 5, /), it is attached to the anterior notch of the thyroid ; but we 

 found, moreover, a very long and strong muscle placed along the mesial 'line of its inner sur- 

 face and of that of the thyroid, which muscle, apparently at least, was connected with the 

 muscular layer around the tracheal aii"-sac. 



The trachea of the Greenland whale is, as usually among the Cetaceans, very wide, but at the 

 same time extremely short. In the newborn specimen it had a width of seven and a half inches 

 and a length of about four and a half inches. It has already been stated that its cartilaginous 

 rings do not enclose the ventral, surface of the tube. The three hindmost rings, however, form 

 an exception in this respect. They are placed very close to one another, and are exceedingly 

 irregular, being frequently split or turned in different manners. As the cricoid cartilage is 

 united with the anterior ring, so the latter is again united with the two next following. 



A very remarkable deviation in the trachea of the Greenland whale, not only from that of 

 rorquals, but, as far as we know, from that of Cetaceans in general, has already been noticed by 

 Sandifort, and thus it only remains for us to corroborate it in its full extent — we mean the 

 peculiarity of its being only bifurcated into two bronchi, that branch which in other Cetaceans 

 (and several land mammals) issues from the trachea before its division into those two bronchi 

 not being found here. The two tracheal branches have not quite the same width ; that of the 

 right one is somewhat larger than that of the left. 



After having followed the cartilaginous respiratory canals to their hindmost extremity, we 

 must yet glance at then- very foremost extremity at the outkt from the nostrils. 



The air-reservoirs situated immediately inside the nostrils of the toothed-whales are very 



generally known, and their rather complicated structure has found several describers, especially 



in the porpoise. That no such superadded cavities are to be found in the right-whales has already 



been shortly stated by Roussel de Vanzeme.^ In examining more closely our newborn cub and 



•^ ' Annales des Sc. Nat.,' sec. ser., tome ii, p. 125. 



