2o8 NERVE COMPONENTS OF BONY FISHES. 



Trigla is the only one of the teleosts for which anything 

 like the condition in Menidia has been described, Stan- 

 nius (p. 25) mentions a fine-fibred nerve which separates 

 from the trigeminus root intra-cranially and after emerg- 

 ing by a separate foramen into the orbit enters a small 

 ganglion. From this ganglion, which is, undoubtedly, 

 the profundus ganglion, as Allis ('97, p. 538) has main- 

 tained, there are given off a ramus ciliaris longus and a 

 radix longa ad ganglion ciliare, very much as in Menidia. 



Allis in the passage last cited has given a very compre- 

 hensive review and critique of the literature of the 

 ophthalmicus profundus which need not be again sum- 

 marized here. The primitive profundus nerve probably 

 contained dorsal and ventral branches. The former is 

 represented by the portio ophthalmici profundi of Amia 

 and in teleosts it is either fused with, or supplanted by, 

 the r. ophthalmicus superficialis trigemini. It cannot be 

 identical with the latter nerve for in several forms both 

 nerves are present. With it may be associated more or 

 less closely the ramus ciliaris longus. The ventral branch 

 comprises the ophthalmicus profundus of selachians and 

 most higher forms and is associated with the radix longa 

 of the ciliary ganglion. 



Amia, as usual, exhibits a transitional stage in the evo- 

 lution of the teleostean specialization. Here the pro- 

 fundus root has fused with the V root, but the ganglion 

 is widely separated. From the dorsal angle of the gan- 

 glion is given off the large portio ophthalmici profundi, 

 which joins the r. ophthalmicus superficialis V. The two 

 rami ciliares longi arise in connection with it from the 

 profundus ganglion. From the ventral angle of the gan- 

 glion the radix longa is given off, while the very small r. 

 ophthalmicus profundus sensu stricto arises from the gan- 



