595 



Nachdruck verboten. 



Further Obseryations on the Cranial Nerves of Chimaera. 



By F. J. CoLE and W. J. Dakin. 



With one Figure. 



The material ou which these notes are based consists of a male 

 Chimaera monstrosa 58 cm long without the caudal whip, and two 

 females of Chimaera (Hydrolagus) colliei — one an entire specimen 

 31 cm long and the other a detached head of a somewhat larger 

 animal. For the two latter we are indebted to the friendly interest 

 of Professor Bashford Dean. 



Innervation of the Supra-orbital Canal. — In a former 

 memoir ^) one of us described two sense organs of the above canal as 

 supplied by the profundus nerve. As this innervation was obviously 

 an impossible one it was stated at the time that some explanation of 

 it would be forthcoming, and that in the meantine no importance 

 should be attached to the anomaly. The explanation predicted was 

 supplied by R, H. Burne 2), who showed that the profundus branch in 

 question was joined by two twigs from the ophthalmic lateral line 

 nerve. This is not of course an absolute demonstration, as pointed 

 out by Burne himself, but we quite agree with him that the lateral 

 line fibres fusing with the profundus branch must be those that 

 supply the canal. We have looked carefully into this point in our 

 specimens of C. colliei, and, although some of the smaller details differ, 

 we can substantially confirm Burne's account. Here also two twigs 

 leave the lateral line nerve and fuse with that branch of the profundus 

 apparently supplying the sense organs in question. 



Ophthalmicus superficialis trigemini. — In the work 

 on Chimaera just referred to the ophthalmic division of the fifth, which 

 is greatly reduced in this fish, is stated to be variable, one important 

 variation being that it may remain entirely distinct from the lateral 

 line nerve of the same name coming from the seventh (op. cit., p. 646). 

 We consequently looked into this point carefully in the present spe- 



1) Cole, Trans. R. Soc. Edinburgh, Vol. 38, 1896. 



2) Proc. Zool. Soc. London, 1901. 



38* 



