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THE AMERICAN NATURALIST [Vol. XL 



elsewhere in which the epiglottis is behind the A^elum or in front 

 of it, and thus does not permit of a supplementary breathing 

 through the mouth also (see Boenninghaus, : 03, p. 84). Still, a 

 similar topographical relation of the parts in question does not 

 correspond to similar physiological phenomena, since in the 

 Sirenia the velum palatinum and the epiglottis are very short 

 (dugong, Owen, '38, p. 36; manatee, Waldeyer, '80, p. 245; 

 Murie, '70, p. 178). 



The dugong takes breath quickly, closes its nostrils, and sinks 

 into the water. The closing results from the fact that the base 

 of the nostril is raised as a slight eminence and pressed tightly 

 against the top. It is interesting to observe that this procedure 

 was also kept up while the animal was lying on the shore, and 

 after each inspiration the nostrils were fast (dosed imtil the next 

 breath was taken. According to Finsch, the closing of the nos- 

 tril takes place through the action of a muscle which he does 

 not indicate further. Riippel ('34, p. 101) makes the incorrect 

 statement that the nostrils can be hermetically closed by valves 

 opening inwards and tins fallacy is re{)eate(l by Brandt ('4G-'69, 

 p. It i. NNonliy „r n<.t.' that Turner .'\)[, pp. 319, 322, 



32(1) found in the cnihrvo and in the head ot' an adult dugong, 

 valves I" valvc-likc liap," "j)lug-hk(" valv(>""i. Xo trace of such 

 a valve can be demonstrated. The same snuciure, it has been 

 claimed, has been found in the manatee. P)iau(h has previously 

 asserted that in the Sirenia "apertiu-ac tui^ah's vaUulis clau- 

 dendae esse." Garrod ('77, p. 139) plainly speaks of a "Hap 

 valve" which forms tlie l)ase of the nasal passage during the act 

 of breathing but rises and completely closes the nostrils when it 

 is shut. Likewise Brown f'78. d. 292). (Iiaonuin r'7,'). n. 401 V 



