—p. 1360 — 



of Seydel's process in Urodela. According to Kulczycki, there is also no recessus lateralis for 

 Jacobson's organ in Porolep i s . 



to 1. I. Shmal'qauzen (1964), the external pa.. ... .... r - 



of the canal. Thomson 1?64 considers that most probably blood vessels and nerves passed across the 

 fnterlor postnasal opening into the nasal cavity. The existence of an externa posterior nans ,n 

 Rhipidistia is somewhat doubtful. This doubt is produced by a new discovery of the skull of 



• rior external naris was noted in this genus (Vorob'eva, 1962), it 



Df the described skull after its 



Panderichthvs . Although, the poster 



"false" nares of the Dipnoi which were formed by it 



A contrasting opinion was expressed by A. N. 



of one of the 



essels and neural branches) in the 

 asobasal canal c 



anch n. profundus across the anterior nasal wall of fossa apicalis (fig. 4, 1, c. 



tic of the Osteolepiformes group only. However, this canal was also found by Kulc 



nasal cavity of Rh 

 bra 



lidi st ia 



As was noted above, the interpretation of some canals (bl( 



debated. Jarvik considers that the nasobasal canal giving off the 



's character- 

 cycki in Porolep i s . 

 On the other hand, the orbital-rostral passage is not surrounded by it which, according to Jarvik, 

 is characteristic of Porolepis . The canal conducting the lateral branch n. prof undus ( f 1 g. 4, 4, r. 

 prl) across the lateral part of the postnasal wall of Porolepis would, according to Thomson, more 

 likely conduct blood vessels into the nasal cavity. 



1361- 



iinqle neural canal leading from the 



Jarvik also considers that in Osteolepiformes there 

 nasal cavity upward to the dorsal surface of the ethmoid, but in Porolepis a multitude of such canals 

 penetrate the dorsal part of the medial wall, the neighboring parts of the prenasal wall and the 

 medial part of the testum nasi. In addition, the nervus profundus which is weakly developed in 

 Eusthenopteron is well developed in Porolepis (fig. 4: 1, 3, "• Pi"). In Porolepis the medial nasal 

 branch (fig. 4: 3, r. prm) in the nasal cavity divides into many 



--fig. 4-- 

 dorsal branches. At the same time, Thomson finds that n. profundus is developed approximately 

 identically in Porolepis . Eusthenopteron and Ectosteorhach i s (fig. 4: 2). However, the canal trans- 

 versing the dorsal wall of the nasal capsule of Porolepis relates more closely to the nervus 

 opthalmicus superf ac ial is VII than to the nervus profundus V. 



In regard to quantity of apertures on the posterior nasal wall for n. profundus, there car, be 

 several variants. In particular, in Osteolepiformes there is one large (Platycephal i chth^s) or 

 relatively narrow ( Eusthenopteron . Eusthenodon ) aperture (fig. 3= 1» c - P r )> but ]i can als0 be 



