The Smooth Facial Muscles of Anura und Salamandrina. 325 



entirely with Wiedersheim in regard to the location of the nasal 

 turbinal. In view of this fact and of the results of my own study, 

 I conclude that the turbinal of the Salamandrina, is to be found 

 only in the region of the planum terminale, which forms a prominence 

 on the wall of the nasal cavity, sometimes by bending inward (Tri- 

 ton cristatus, Salamaudra atra], sometimes by a mere thickening of 

 the cartilage (Plethodon, Desmognathus). In some cases, however 

 (Salamandrina perspicillata), a real prominence is barely or not at 

 all recognizable, although the general structure of the nasal wall is 

 otherwise the same as in other Salamandrina. It follows from the 

 above that the nasal muscle thickening of the salamander 

 can not represent the turbinal, which, in fact, begins at 

 the caudal end of the muscle thickening and extends in a 

 posterior direction. 



3. The nasal Muscles and the Glandula nasalis externa. 



The glandula nasalis externa of the Salamandrina has been 

 frequently observed, but was first accurately described by Seydel 

 (45), who located its opening upon the posterior margin of the aper- 

 tura naris externa. The position of the gland in the nasal muscle 

 thickening has been already referred to (see Fig. 1 , PL XVII). There 

 arises, however, the question, whether the close relation between the 

 nasal muscles and gland is of functional importance. The point of 

 discharge of the gland shows that the secretion is intended for the 

 nasal opening and its immediate vicinity; moreover, a moist condi- 

 tion of the margins of the nasal aperture must be of considerable 

 importance in facilitating the secure closing of the opening, and it 

 would be especially advantageous if the moistening of the naris 

 should occur just at the moment of closing. We are led, therefore, 

 to the consideration of the question, whether the contraction of the 

 nasal muscles is able to influence in any way the discharge of the 

 glandular secretion. To solve the problem we must study somewhat 

 accurately the relation existing between the nasal muscles and the 

 gland. For this purpose I shall employ 



1) Triton alpestris. In this species the glandula nasalis externa 

 lies chiefly within the bounds of the fenestra rostro-lateralis; only a 

 few tubules extend farther caudalward and terminate near the ductus 

 naso-lacrymalis, between the planum terminale and the facial process 

 of the maxillare. In the posterior and lateral parts of the fenestra 



