Oa the Anatomy and Phylogenese Position of Polypterus. 397 



The root of the ophthalmicus sup. aucl buccalis is ganglionic for a 

 considerable portion of its extent. Before the chief ganglionic swelling 

 a branch of considerable size is given otf within the skull wall. This 

 branch sends out two smaller branches to the mucous canal in the 

 postfrontal and posterior suborbital and a branch which passes down- 

 wards and joins the maxillaris superior from which however it is 

 separable. It continues on over the masseter where it divides into 

 several branches which run down to the region behind the articulation 

 of the jaws. These branches were figured by Müller who thought 

 they were motor branches to the masseter. 



The Ramus mandibularis is well described by van Wi.jiie. The 

 mandibularis internus, the alveolaris of von Plessen and Rabinovicz 

 appears to correspond in course and position with the chorda tym- 

 pani of mammals. It runs between the purely dermal metapterygoid 

 and quadrate. 



The Ramus hyoideus is a posttrematic branch which supplies the 

 Retractor hyomandibularis and opercularis, the muscles of the oper- 

 cular flap and the intermaxillaris posterior. 



The Glossopharyngeus gives ofl a fine branch which passes 

 dorsally and vertically upwards and penetrates the process of the Pe- 

 trosum. It appears to supply the skin above ^). The posttrematic branch 

 supplies the 1st levator arcuum and the 1st interarcualis ventralis. 



In the Vagus pharyngeal, pretrematic and posttrematic branches 

 may be easily distinguished. The Ramus supratemporalis consists 

 of several fairly stout branches. The last gill branch cannot be said 

 to give otf a pretrematic branch. There is no 5th gill slit and the 

 nerve is small The Ramus recurrens closely corresponds to a post- 

 trematic branch. It supplies muscles behind the gills which in higher 

 animals enter into the service of the larynx. Certain of the nerves 

 of Polypterus may be grouped in the following manner: 

 see page 398. 



After giving otf the Ramus recurrens the vagus divides into two 

 large branches, the upper being the Ramus intestinalis which has a 

 long course accompanying the intestine and the lower being the Ramus 

 bronchialis to the swimbladder. On reaching the latter the nerve 

 divides into many branches some of which proceed forwards to the 

 laryngeal opening but the majority pass a considerable way down 

 the body. 



1) It doubtless supplies one of the mucous canal organs. 



Zool. Jabrb. V. Abth. f. Morph. 27 



