116 



hind the orbital part of the os frontale, which position is by some supposed to 

 be the normal one. This can not be brought about by the action of the muscle, 

 since as appears from the sketch, in that case the place of attachment, g, 

 would have to be withdrawn further backwards, (behind ƒ, the posterior 

 part of the orbit), than is possible. 



This would be possible only in case the attachment of the muscle were 

 located a long way anterior to the processus coronoideus. 



On placing the lower jaw all the same in such a position that the processus 

 coronoideus is couched in the temporal fossa behind the orbital part of the fron- 

 tale, we obtain the singular result that the condyles of the inferior maxillae reach 

 some way behind any part of the skull, whilst in front the upper jaw would 

 stick out, so that the space between the lower jaws would become too small 

 for the down-hanging baleen-plates. 



To occupy this position the inferior maxillae of the Buitenzorg Balae- 

 nopter would have to be moved backwards at least 95 c.M., whereas we have 

 previously found that they might safely have been produced forward a little 

 more than in the existing reconstruction without causing unnatural proportions. 



As a matter of fact I have never seen a position similar to that advocated 

 by my critics in any picture representing the reconstruction of a whale skeleton, 

 although indeed the differences in the reconstructions are many. The sketch 

 shows how on the basis of all the facts and arguments adduced in the 

 preceeding paragraphs, I conjecture the true position of the lower jaw relative 

 to the skull; which position was accordingly given to it in the construction of 

 the Buitenzorg skeleton. 



Furthermore this reconstruction agrees substantially with the somewhat 

 vague illustration, referred to before from True (6) pi. 36 fig. 1, reproducing 

 the skull of Megaptera nodosa Bntr, a Balaenopter from the Niagara-Falls 

 Museum in New-York, described in the index to the plates as: ,, Skull from 

 the type-skeleton". The lower jaw in this instance is placed in a slightly more 

 advanced and lowered position than in our case. 



The tongue-bone (hyoid bone) (fig. 9) presents a strong resemblance to 

 that of Balaenoptera musculus L. according to the illustration in Reinhardt (5) 

 p. 189, with the only difference that in the Buitenzorg skeleton the great poste- 

 rior horns of that bone are somewhat heavier and less constricted in girth 

 towards the basal end. 



