556 



NASAL SECBETORT SACS IS TELEOSTEI 



Fig. 2. Semidiagrammatic longitudinal section through the skull of Solea 

 lascaris, to' show the nasal sacs, r.w.s. and l.n.s. 



3. Cynoglossus semilcsvis: a dissection from the left side, showing the left 



olfactory organ (o.L), the mandibular tooth-mass of the right side 

 {t.?n.), and indicating, diagrammatically in dotted lines, the course of 

 the left naso-pharyngeal canal {n.p.c), and the position of the 

 aperture of the naso-pharyngeal sac (c). 



4. The same : ventral view of the roof of the mouth, showing the 



aperture of the naso-pharyngeal sac (c), and, diagrammatically in 

 dotted lines, the course of the naso-pharyngeal canals (n.p.c). The 

 arrows point towards the internal openings. 



5. The same : a dissection to the level of the naso-pharyngeal sac, the 



left wall of which (c.f.) has been turned outwards to show the course 

 of the left naso-pharyngeal canal (n.p.c), and the slit- like expansion 

 of the naso-pharyngeal canal of the right side (u.c) as it opens into 

 the sac (c). 



Reference 



b., basioccipital. 

 b.v., breathing- valves. 

 c, sac in roof of mouth into which 

 the naso-pharyngeal canals 

 open. 

 c.f., cut edge of fold round sac (c). 



e., ethmoid. 

 e.l., left eye (displaced). 

 e.o., opening of naso-pharyngeal 

 canal into nasal cavity. 

 /., fold round naso-pharyngeal 



sac (c). 

 fr., frontal. 

 ft., fatty tissue. 



h., hyomandibular. 

 i.m., premasilla. 

 l.n.s., left nasal sac. 

 l.i.m., left premaxilla. 

 Lm., left maxilla. 

 OT., maxilla. 

 M., mouth. 



Letters. 



