394 ^- ^- POLLARD, 



The muscle arisiog from the last ceratobranchial and attaching itself 

 by tendon to the 2nd and 1st ceratobranchial was apparently inner- 

 vated by the hypoglossal but on this point unfortunately 1 could not 

 become quite certain. Should its innervation be found to be from the 

 Vagus it would correspond to the Constrictor arcuum visceralium of 

 Urodeles. 



In Polypterus from the last ceratobranchial to a median raphe 

 extends a broad sheet of muscle supplied by the Ramus recurrens vagi. 

 This sheet in Urodeles becomes ditierentiated to certain muscles of the 

 larynx. 



The condition in Urodeles of the ventral longitudinal muscles be- 

 longing to the body and not really to the visceral system may be de- 

 rived from that in Polypterus allowing for the total loss in the former 

 of the dermal clavicle and interclavicle. 



In conclusion it may be stated that the anterior muscula- 

 ture of Polypterus shows on the one hand some charac- 

 ters derivable from the lowest Selachii, on the other 

 hand leads directly to the condition of the Urodeles. 



Peripheral Nervous System (figs. 7 and 8 etc.). 



The nerves of Polypterus have been already well described by 

 VAN WijiiE and the following must therefore by regarded partly as 

 supplementary to his description but mainly introduced for the sake 

 of comparison with other animals. 



Third or Oculomotor group. Belonging to this group are 

 th(! Ophthalmicus profundus and oculomotor nerves. The root of the 

 Ophthalmicus profundus arises apparently from the mid brain on a 

 level with or slightly anterior to the root of the oculomotor. Certainly 

 it is far separated from the root of the Trigeminus. Usually owing 

 to poor preservation the brains of Polypterus are difficult to study 

 but the nerve roots themselves remain and in the Ophthalmicus pro- 

 fundus indicate clearly the independence ot origin from the Trigeminus 

 roots. Beyond its ganglion the Ophthalmicus profundus of Polypterus 

 may be said to give off" 3 nerves : (1) the commissures to the Ophthal- 

 micus superficialis of the Facial, (2) the Ophthalmicus profundus in 

 narrower sense, (3) a branch which joins the motor nerves. These 

 three branches might be called upper, median, and lower respectively. 



The median branch after taking the course described by van 

 Wi.THE to the canal in the ectethmoid bone, which it occupies together 

 with the Ophthalmicus superficialis, the Obliquus superior muscle and 



