470 Edward Phelps Allis jr., 



The other line, "eÄ", would seem to find its homologue in the line 

 of surface organs that I have described on the operculum of Conger. 

 The latero-sensory lines of Lophius, while they can thus he quite 

 probably correctly homologized with the lines in other fishes, differ 

 greatly in their general arrangement from those in all the other 

 living fishes that I can find descriptions of, excepting only Chaunax 

 pictus. In this deep-sea and closely-related fish, the sensory lines, as 

 shown by Günther [43, pi. X], agree, in a general way, with those 

 of Lophius. The groove of the lateral line of the body is continued 

 forward directly into the supraorbital groove of the head, the con- 

 nection apparently taking place at the anterior end of a section of 

 the groove that would correspond either to the temporal section of 

 the line in Batrachus, or to an otic section. Posterior to this point, 

 there is apparently a cross-commissural line of surface organs that 

 would represent the supratemporal line. The infraorbital and preoper- 

 culo-mandibular lines would seem to correspond with those in Lophius, 

 but the dorsal end of the preopercular line does not quite meet the 

 temporal line, and there are no posterior extensions of the mandibular 

 and suborbital lines. This arrangement of the latero-sensory lines, 

 and hence also that in Lophius, will be later shown to represent the 

 closest known approach to the arrangement shown in certain of the 

 early fossil fishes. 



Elasmobranchii. 



The only works that I can find that give either the position, or 

 the innervation, of the organs in the latero-sensory canals of elasmo- 

 branchs, are Ewart's [36] descriptions of Laemargus, Ewart and Mit- 

 chell's [37] descriptions of Eaia, Cole's [25] descriptions of Chimaera, 

 Coggi's [22 — 24] descriptions of Torpedo, and my own [8] descriptions of 

 Mustelus. All that is important, in these several works, in connection 

 with the present discussion, can be shortly resumed as follows: 



In Mustelus, the supraorbital canal anastomoses, by its terminal 

 tube, with the anterior end of the otic section of the main infra- 

 orbital canal, and the supraorbital sensory line is not continued 

 posteriorly, beyond this point, by a line of pit organs. The entire supra- 



