No. 2.] AM/A CALVA. 487 



There is, however, a large and important portio ophthalmic! 

 profundi (van Wijhe), single or double, lying dorsal to all the 

 muscles and nerves of the eyeball, and corresponding therefore 

 to those frontal branches of the ophthalmicus profundus that 

 have a similar relation to those nerves and muscles, such as 

 branch i of Ewart in Laemargus. 



8. The ramus ophthalmicus superficialis trigemini, in Amia, 

 also lies dorsal to all the nerves and muscles of the eyeball. 

 It cannot therefore be sometimes found in other fishes or in 

 Amphibia fused with the ramus ophthalmicus profundus, as is 

 generally assumed to be the case, unless in such cases the 

 superior branch of the oculomotorius and the nervus trochlearis 

 are found as apparent branches of the compound-nerve so 

 formed. Where such is not the case, and where the ramus 

 ophthalmicus trigemini has the relations of a profundus to the 

 nerves of the muscles of the eyeball, as in selachians and 

 Amphibia, the ramus superficialis, if it exists, must be repre- 

 sented by so-called frontal branches given off by the ramus 

 ophthalmicus before it passes under the rectus superior muscle. 



9. The ramus palatinus facialis in Amia arises entirely from 

 that part of the trigemino-facial ganglion that is formed on the 

 fasciculus communis root, and its distribution to regions where 

 terminal buds abound is such that it must be concerned in the 

 innervation of those organs, although branches of the nerve 

 could not be definitely traced to any of them. In Rana, Strong 

 states definitely that it innervates certain of those organs. 



10. The ramus ophthalmicus superficialis trigemini, in Amia, 

 also arises mainly, if not entirely, from that part of the tri- 

 gemino-facial ganglion that is formed on the fasciculus com- 

 munis root, and it is concerned in Amia largely, if not entirely, 

 in the innervation of terminal buds. That part of it that is so 

 concerned should, therefore, be considered either as a branch 

 of the palatinus facialis or as homodynamous with that nerve. 

 As there are no terminal buds, or but few, on the top of the 

 head and snout in selachians and Amphibia (Merkel), the nerve 

 is naturally wanting or small in those forms. 



1 1 . The rami maxillaris superior and maxillaris inferior tri- 

 gemini each receive an important part of their fibres from the 



