124 EDWAED PHKLPS ALLIS, JUN. 



orbital. In that case the two nerves of Mustelns tliat inner- 

 vate organs 79 to 86 would be the homologues of the nerves 

 that in Amia innervate organs 11 to 13. It seems to me, 

 however, much more probable that these latter nerves in 

 Amia have their homologues, in Mustelus, in the nerves that 

 innervate organs 87 to 96, the nerve that innervates the 

 spiracular organ in the two fishes not having exactly the 

 same course and possibly not being exactly the same nerve. 

 However this may be, it is evident that either organs 87 to 

 110, or organs 79 to 110, must represent organs 11 to 16 of 

 Amia, and that the nerves that together innervate the organs 

 in the two fishes must be homologous. These several organs 

 in Mustelus, Nos. 87 to 110, or 79 to 110, as the case may be, 

 and organs 11 to 16 in Amia, thus form, in each fish, a group 

 of organs that is quite distinct and separate, in its innervation, 

 from the remaining more anterior infra-orbital organs. In 

 Amia these organs also develop somewhat separately and 

 independently from the rest of the line (2). As this same 

 grouping of these organs is found in Scomber also (7j, it 

 would seem as if it might be considered as a general rule that 

 there are, posterior to the anterior, antorbital group of organs, 

 tAvo separate and distinct groups of buccal organs in the main 

 infra- orbital line. The anterior one of these two groups, plus 

 the antorbital group of organs, must then correspond to the 

 organs innervated by the outer buccal nerve of Cole's descrip- 

 tions of Chimsera, and the other group to the organs inner- 

 vated by his inner buccal nerve. They must also correspond 

 to the two groups innervated by the inner and outer buccal 

 nerves of Cole's descriptions of Gadus (12), and to those 

 innervated by the buccalis and oticus facialis of Herrick's 

 (32) descriptions of Menidia. But, in Cole's application of 

 these names, inner and outer buccal, to the nerves in Gadus, 

 adopted by Herrick (33) in his descriptions of the same fish, 

 it is the outer buccal that innervates the posterior group of 

 organs, and the inner one that innervates the anterior one, 

 the reverse of the conditions described by Cole in Chimaera. 

 That this is due to an error in homologisiug the nerves in 



