436 Cranial Nerves of Elasmobranch Fishes. Presents. [Mar. 7, 



lengths obtained for the aurora line were 5595, 5586, and 5587. 

 Unlike most observations, these place the aurora line on the less 

 refrangible side of the manganese fluting. Hence, we have an addi- 

 tional reason for neglecting the difference between the wave-length 

 of the brightest edge of the manganese fluting, and the commonly 

 accepted wave-length of the aurora line, as given by Angstrom. 

 . . . . These observations are the latest which have been pub- 

 lished, and were obviously made with a full knowledge of all previous 

 work, so that their importance must be strongly insisted upon." 



I have already pointed out that Krafft's measures were not made 

 under circumstances which assured to them a high degree of accuracy ; 

 and Krafft's own words, which I have quoted, disclaim expressly any 

 special attempt on his part to redetermine the position of the principal 

 line with a higher degree of accuracy than the observers who preceded 

 him. March 4.] 



III. " On the Cranial Nerves of Elasmobranch Fishes. Prelimi- 

 nary Communication." By J. C. EWART, M.D., Regius 

 Professor of Natural History, University of Edinburgh. 

 Communicated by Professor B. SANDERSON, F.R.S. Re- 

 ceived February 22, 1889. 



[Publication deferred.] 



Presents, March 7, 1889. 

 Transactions. 



Dijon : Academic des Sciences, Arts et Belles-Lettres, Memoires. 



Annee 1887. 8vo. Dijon 1888. The Academy. 



Dublin: Royal Irish Academy. Transactions. Vol. XXIX. 



Part 5. 4to. Dublin 1889. The Academy. 



Edinburgh : Royal Scottish Society of Arts. Transactions. Vol. 



XII. Part 2. 8vo. Edinburgh 1889. The Society. 



Royal Society. Proceedings. Vol. XV. Nos. 126-127. 8vo. 



Edinburgh 1888 ; Transactions. Vol. XXXIII. Part 3. Vol. 



XXXV. Part 1. 4to. Edinburgh 1888-89. The Society. 



Leipsic : Astronomische Gesellschaft. Vierteljahrsschrift. Jahrg. 



XXVI. Heft 4. 8vo. Leipzig 1888. The Society. 



London : East India Association. Journal. Vol. XXI. No. 1. 



8vo. London 1889. The Association. 



Odontological Society of Great Britain. Transactions. Vol. XXI. 



No. 4. 8vo. London 18b9. The Society. 



