210 ANATOMY OF VERTEBRATES. 



the nasoturbinal as it advances : the maxilloturbinal is shorter, 

 relatively broader and deeper, and much more extensively folded 

 than in the Lion. This is the part of the olfactory organ that 

 reaches the extreme of turbinal development in the Seal-tribe. 

 In the large species dissected for the preparation, No. 1557, the 

 maxilloturbinal is attached by its contracted extremities, the 

 intervening enormously swollen mass is divided by a deep longi- 

 tudinal furrow into two parts ; the free surface of which is singu- 

 larly complicated by folds, radiating from both extremities of the 

 bone and subdividing dichotomously. 1 These turbinals seem to 

 block up the entry of the nasal respiratory passages, and must 

 warm the air in arctic latitudes as well as arrest every indication 

 from the effluvia of alimentary substances or prey. The nasotur- 

 binals, in some Otariae, extend backward, with the nasal chamber, 

 above the long rhinencephalic compartment of the cranium. 



In the Quadrumana the nasal chamber loses length and gains, 

 but in less proportion, depth and breadth, from the Lemurs up 

 to the Apes : the maxilloturbinal ceases to be suspended by its ex- 

 tremities, and acquires a linear longitudinal attachment externally 

 to a ridge on the maxillary wall of the nasal chamber. This tur- 

 binal is divided into two chief parts lengthwise, in Lemuridce, where 

 it is longest : the nostrils are here terminal, the anterior expan- 

 sion of the septal cartilage curves outward and downward on 

 each side, and, with a corresponding degree of curvation of the 

 principal alar cartilage, gives a subconvolute form of nostril 

 to most Strepsirhines. In the Aye-aye they describe a semi- 

 circle ; and the nasal chamber by its shortness, depth, and pre- 

 dominance of the ethmo- over the maxillo-turbinals exemplifies 

 the quadrumanous affinities of the species. 2 In Platyrhine 

 monkeys, the septal cartilage is remarkable for the transverse 

 extent of its anterior terminal expansion between the nostrils, 

 pushing them and their alar cartilages outward. In Catarrhines 

 this expansion is much reduced ; and the nostrils are obliquely 

 approximated. In both groups the nostrils cease to be ter- 

 minal ; in a Bornean Douc ( Semnopithecus nasicus\ the nos- 

 trils are produced upon an ill-shapen prominent subcylindrical 

 nose. In the Gorilla each nostril is surmounted by a broad 

 prominence, arching outward from a lower part impressed by a 

 median furrow ; a deeper indent divides the nasal ala from the 

 cheek : the aspect of the nostrils is forward and a little out- 

 ward. The septal cartilage extends to the tip of the interalar 

 prominence. 



1 xx. vol. iii. p. 100. : cn'. p. 18, pi. viii. fig. 6. 



