1901.] FIYE-HOItXED GIRAFFE FROM MOUNT ELGOX. 477 



The following are the measurements in millimetres of the four 

 Elgon skulh, which being all perfect, wild-killed specimens, fully 

 adult, may afford a standard for comparison with specimens from 

 other localities : — 



(old). (adult i. 



Extreme length (mesially) G88 081 



Basal length '. 593 598 



Greatest breadth 32] 273 



iXasal opening, length from gnathion 



to junction of nasals with pre- 



inaxilla 157 174 



Do. breadth 72 To 



Muzzle to orbit 386 386 



Distance between tips of horns 



(centres) 157 176 



Muzzle to front of anterior premolar. . i'47 L'47 



* 



,. 



642 



622 



."•77 



564 



17'.' 



277 



174 



161 



69 



65 



375 



359 



83 



135 



•J4(l 



l>43 



Secondly as to the structure, homologies, and evolution of the 

 posterior horns, which, as already said, are present in some degree 

 in all Giraffes, or at least in all male Giraffes. These structures, 

 on the analogy of the masts of a ship, it may be convenient to 

 speak of as " mizen " horns '. 



Externally, although of no great length, even where most de- 

 veloped, they yet show a certain community of structure with the 

 other horns, as the hairs are similarly whorled around and over 

 them, and in colour, like the other three, the}' are yellowish below, 

 crowned with black terminally. 



Turning to the skull, the first drawing (text-tig. 4.*i p. 478) 

 shows the back part of the oldest male cranium of the Johnston 

 >eries (that belonging to the head shown in text-tig. 42, p. 476). 

 A section has been made through the posterior projection to 

 show its thickness and the extent to which the cranial vacuities 

 penetrate it. 



Here it will be seen that the mizen horn is placed behind the 

 end of the masseteric fossa of the parietals. in front and quite 

 clear of the supraoccipital one for the attachment of the nuchal 

 tendons and muscles. The horn is always just in this position; and 

 u hen examined in a young specimen (text-fig. II. p. 17 s I appears 



to '"• on the antero-external angle of the combined interparietal 

 and Bupraoccipital, close behind the parietal suture. Bui in old 

 animals it no doubt trespasses on the latter bone. 



Some sort of a swelling may be perceived at this point in every 

 male ( lira He's skull, even in such as would be at once said to have 

 no mizen ■• horns.* 1 Taking, For instance, an old male skull from 



' The word " posterior" irould !><• fruitful of confusion with the main borne, 

 which are the posterior ones in animals without misen borne; " oooipital " is 

 equallj objectionable, on aoooun( >>\' the varying position with regard to th< 

 cranial bonei ol all three pain of borne; " fore, " main," and "misen" can 

 L 'i\>. rise i" bo ambiguity. 



Pboo. Zool. Soo.— 1901, Vol. II. No. XXXII. 32 



