No. 2.] LINE SYSTEM OF BATRACHUS TAU. 235 



There seems to be an interesting peculiarity in the innerva- 

 tion of the body lines of Batrachus. The N. lineae lateralis 

 does not supply the line of sense organs continuous with the 

 infraorbital of the head, but it does send branches to some of 

 the scattered organs of the middle line. The dorsal and ven- 

 tral lines of the body are innervated, in part at least, by the 

 R. recurrens facialis. This nerve emerging from the ve^itral 

 branch of the dorsal VII (Fig. 13) turns directly backward 

 within the cranial cavity; it passes obliquely through the cranial 

 wall and through a loop in the glosso-pharyngeal, beyond 

 which it forms an anastomosis with an ascending branch 

 from the posterior root of the vagus, at a point just behind the 

 auditory capsule. The position of the R. recurrens facialis is 

 superficial to the N. lineae lateralis, and it extends on to the 

 body just underneath the skin. It divides immediately (Fig. 

 22), sending one branch toward the dorsal region supplying 

 the organs of the anterior portion of the dorsal line, while the 

 ventral branch curves around behind the base of the pectoral 

 fin innervating the anterior organs of the ventral line. 



The X or vagus nerve. — The anterior root of the vagus 

 nerve arising from the dorsal region of the medulla (Fig. 12, 

 X an.r.), does not possess any distinct ganglion. It runs 

 backward and outward, crossing the main root of the vagus, 

 with which it is connected by a few fibres, and after leaving 

 the cranium by the foramen in the occipital is continued on 

 the body as the N. lineae lateralis. It courses deeply under- 

 neath the muscles for some distance, becoming superficial at 

 the posterior portion of the body. 



Although this is the main lateral line nerve, it seems to 

 innervate only a few of the organs on the body of Batrachus. 



The supratemporal branch of the vagus is composed mainly 

 of anterior root fibres (Fig. 13, st.v.'^). It arises intracranially, 

 passing upward and leaving the skull through a foramen in the 

 supraoccipital (Fig. 4, o.c.f). It then turns forward, supplying 

 the canal organ of the temporal region (Figs. 22 and 23) and 

 three other organs on the top of the head. The most anterior 

 of the three organs may be considered as representing the 

 middle dorsal line of pit organs, which in Amia are innervated 



