THE LATERAL LINE ORGANS. 41 



back from in front of the eye is suggrested by the course of 

 its nerve, which first runs forward cephalad of the eye 

 and then sends recurrent twigs to supply the line back to 

 the point where it joins the opercular line. The line o-c 

 represents the supra-orbital canal of Menidia. It is prob- 

 able that the organs belonging to the r. oticus are also 

 included here, for the last organs of this line are inner- 

 vated by a separate branch of the r. ophthalmicus 

 superficialis VII. Upon comparing the diagram of 

 Lophius with Allis' diagram of the lateral line system of 

 Amia, it is suggested that the line o-p is the occipital 

 commissure and its pit-line of Amia, the line o-b is the 

 middle pit-line, while the anterior pit-line is represented 

 in the caudal part of the line o-c. This last supposition 

 would explain the fact that the supra-orbital line does not 

 join the main line /-^, but the others farther dorsad. 



Material has been collected and some fragmentary ob- 

 servations have been made upon the development of the 

 lateral lines in Menidia, but these results are as yet too 

 incomplete to yield much of value. In very young speci- 

 mens about I cm. long the cutaneous sense organs were 

 plotted and all of the lateral line organs were found in 

 essentially the same relations as in the adult save that no 

 canals are developed. The number and arrangement of 

 the naked lateral line organs is the same as in the adult. 

 In specimens a few mm. longer the canals have begun to 

 appear and when 2^ cm. long the canals have been com- 

 pleted very nearly as in the adult. The pores are in all 

 cases wider at this age than in the adult and the main 

 canal is interrupted for the entire distance between the 

 point of tmion of the supra- and infra-orbital canals and 

 the organ lying next caudad. Only four organs are con- 

 tained in the lachrymal segment of the infra-orbital canal, 



