No. 2.] LINE SYSTEM OF BATRACHUS TAU. 257 



p.n.a. = posterior nasal aperture. 

 P.OP. = preoperculum. 

 p.r. = posterior root. 

 reef. = ramus recurrens facialis. 

 s.or. = sense organ. 

 SO.C. = supraorbital canal. 



sp.c. = spinal cord. 

 st.com. = supratemporal cross-commissure. 

 st.v' . = supratemporal branch of vagus. 

 T.A. = tuberculum acusticum. 

 T.C.^ temporal canal. 

 V. = ventral fin. 

 v.b.rec.f. = ventral branch of recurrens facialis. 

 V.O.I. = ventral opercular line. 

 v.g. = vagus ganglion. 

 V? = second branch of vagus. 

 ■wd. = wolffian duct. 



