322 Henry L. Bruner 



Desraognathus, Triton, Amblystoma) a second dilatator (dilatator naris 

 accessorius) also occurs. 



In my original description (7) of the nasal muscles of the sala- 

 manders, these muscles were considered as related to the apertura 

 naris crauialis externa, and the cartilaginous nasal skeleton did not 

 receive detailed attention. For the purposes of the present paper, 

 greater emphasis is here given to the cartilaginous parts and the nasal 

 muscles are oriented with reference to the fenestra rostro-lateralis. 

 The relation of these muscles to the skeleton and nasal opening in 

 Triton alpestris is the following (compare Fig. 7, PI. XVII): The semi- 

 circular constrictor naris lies in the anterior portion of the fenestra 

 rostro-lateralis and surrounds the posterior half of the nasal opening. 

 The medial insertion of the muscle is the margin of the cartilago 

 obliqua, its lateral end inserts in part on the nasal capsule, in part 

 on the inner surface of the facial process of the maxillare. The 

 dilalator naris arises inside the nasal cavity from the anterior end 

 of the planum terminale (turbinal cartilage) and medial from the 

 anterior end of the lacrymal duct {M.d.n., Fig. 2, PL XVII). This 

 muscle extends forward beneath the constrictor naris, ascends then 

 toward the outer surface and inserts on the caudal margin of the 

 nasal opening. The dilatator naris accessorius arises from the lateral 

 margin of the fenestra rostro-lateralis and inserts on the caudo- 

 lateral portion of the nasal opening. 



As I have shown in another place (7) the attachment of the 

 nasal muscles varies somewhat in different species of Salamandrina. 

 As an addition to my former account, I will here mention the 

 following details. In Salamandra atra Lam*, the dilatator naris acces- 

 sorius arises entirely outside the nasal cavity from the cartilage 

 bridge which lies between the fenestra rostro-lateralis and the fenestra 

 lateralis and connects the planum terminale with the floor of the 

 nasal capsule. A similar relation we find in Plethodon and Des- 

 moguathus, in which, however, the dilatator naris accessorius arises 

 also in part from the outer surface of the intranasale (see 3f.d.?j.a., 

 Fig. 4, PI. XVII). In Amblystoma tigrinum Green the intranasale is 

 relatively large and the dilatator naris accessorius arises from its 

 outer surface. Here the dilatator naris arises in part from the inner 

 surface of the intranasale and partly further caudalward from the 

 planum terminale. 



A summary of literature in which reference is made to the 



