40 NERVE COMPONENTS OF BONY FISHES. 



position and innervation with the pit-Hne o.i to 0.4. in 

 Menidia, and the line d-k to the organ 0.5 on the dorsal 

 surface of the operculum of Menidia. In Batrachus 

 (Clapp, '99) there are lines in these positions like those 

 of Lophiiis. These lines also bear some resemblance to 

 the gular and jugular lines of Chlamydoselachus, and the 

 organ o. 6 to the angular line of the same fish (Garman, 

 '88). The line d-k apparently also corresponds to the 

 posterior limb of the hyomandibular canal of selachians 

 (Ewart, '93) and Chimasra (Cole, '96a), and in the latter 

 cases there are groups of ampullae in the same region, 

 which probably also belong in the same category. In 

 Amia (Allis, '89) there are pit-lines supplied by similar 

 branches of the hyomandibular nerve, but these lines lie 

 cephalad of the opercular canal instead of caudad of it. 



The line f-g of Lophius lies in the same position as an 

 area of thickened epidermis in Menidia under the eye 

 between the infra-orbital and opercular and mandibular 

 canals, an area containing many pit-organs in Gadus. 



The line q-c-n-g-d oi Lophius would at first sight be com- 

 pared directly with the infra-orbital line of Menidia. Yet, 

 in spite of the fact that both lines are innervated by the 

 r. buccalis, the homology is, I think, only incomplete, 

 as shown by the peculiar course of the nerve in Lophius 

 and a comparison with Batrachus (Clapp, '99). In the 

 latter case there is a small (and obsolescent?) infra-orbital 

 line and in addition a "maxillary line" which runs 

 caudad from near the cephalic end of the infra-orbital, 

 laterally of the latter, but does not reach the opercular 

 line. This latter line is more highly developed in Lophius, 

 while the caudal portion of the infra-orbital line, which 

 should connect with the cephalic end of the line l-b, has 

 disappeared. That the line n-g-d of Lophius has grown 



