624 



MR. R. H. BURNE ON THE ANATOMY OF THE [May 25, 



smooth vacant cavity leading from the outer and hinder part of the 

 first segment to the posterior nostril. The addition of this empty 

 accessory sac to the olfactory chamber proper, in which lies the 

 rosette and the possession of valvular lips by the posterior nostril, 

 suggests that in some way water is di-awn forcibly upon the 

 olfactory rosette through the anterior nostril. At first sight the 



Text-fig. 196. 



PMX. 



B 



Clarias lazera. 



A. The olfactoiy organs from above : — On the left the nasal cavit3' opened; 



on the right the relation of the olfactory organ to the skeleton. 

 a. The muscle connecting the hinder end of the palatine bar to the cranium. 



B. Diagram of the laminae of the rosette. 



mechanism by which this is effected is not apparent, the jaws 

 which in Fishes are the usvial agents in such actions being 

 evidently not so in this case. An examination of the rest of the 

 skull in relation to the nasal cavity makes it clear, however, that 

 an intermittent current of water could be, and probably is, 

 produced automatically by the movements that take place between 



