The Smooth Facial Muscles of Anura and Salamandriua. 339 



leads from the eavum medium upward into a lateral vestibule of the 

 cavum superius {V.c.s., Figs. 11 and 13, PI. XVIII), which is bounded in 

 front and laterally by the cartilago alaris, behind by the thickeniDg- 

 of the lateral nasal wall which contains the glandula nasalis externa. 

 This vestibule, which was briefly described by Born, is separated 

 from the cavum superius itself by folds only, of which one connected 

 with the caudal wall of the vestibule attains a considerable size. 

 This fold, which I shall call plica obliqua (see Figs. 8, 9, 13, 14), 

 extends from below obliquely upward and terminates at the medial 

 margin of the nasal opening, where it is attached to the cartilaginous 

 roof of the nasal capsule. The apertura naris externa lies in the 

 dorsal wall of the vestibule of the cavum superius between the 

 cartilago alaris and the roof of the nasal capsule. 



The glandula nasalis externa of Rana fusca lies behind the 

 vestibule of the cavum superius in the above described thickening 

 of the lateral nasal wall {Gl.n.e., Figs. 11 — 14). The caudal part 

 of the gland lies lateral from the planum terminale and dorsal 

 (medial) from the ductus naso-lacrymalis; its rostral part rests upon 

 the lateral arm of the intranasale. Rostrally, the tubules of the 

 gland unite into a short duct which takes a course toward the 

 external naris and opens in close proximity to the same on the inner 

 surface of the plica obliqua (see Fig. 9). From this point of discharge 

 a narrow groove leads to the nasal opening. 



The cartilaginous nasal skeleton of Anura and Salamandriua 

 was described at about the same time by Parker (37) and Born (4), 

 the latter of whom, especially, established the homologies to which 

 I have referred in my account of the general anatomy of the nasal 

 skeleton of Rana and Triton. The terminology employed by me is 

 from the work of Gaupp (22), who also gives a full description of 

 the intermaxillary mechanism which is used in opening and closing 

 the external nares of Rana. 



The intranasale of Gaupp was described by Parker (37) under 

 the name septo-maxillare, a homologue of which Parker found in 

 Amblystoma and other salamanders. From his study of certain 

 Anura, Born (4) was led to the conclusion that the septo-maxillare 

 of Parker represents a lacrymale (fronto-lacrymale and prefrontale 

 of authors). This conclusion was based chiefly on the relation of 

 the septo-maxillare of Parker to the naso-lacrymal duct. The 

 complicated form of the bone in Anura Born attributed to the 



