MUSTEf.US L^<JVIS. 207 



In the same work in which van Wijhe describes the nerves 

 in Polypterus and Lepidosteus, he also describes the nerves in 

 Acipenser. In this latter fish, doubtless misled by Balfour, 

 he first describes an ophthalmicus superficialis trigemini and 

 an ophthalmicus profundus trigemini which have the mutual 

 relations of the superficialis and profundus nerves of Bal- 

 four's descriptions of Scyllium. Later, but in the same 

 work (p. 230), van Wijhe says, in a footnote, that the 

 anatomical position of this so-called profundus nerve pre- 

 cludes its being a ramus profundus, in the sense in which that 

 term is applied in selachians, and he accordingly concludes 

 that the two ophthalmic nerves of his descriptions of Aci- 

 penser are very probably simply the portio major and portio 

 minor of Schwalbe's nomenclature, and hence both integral 

 parts of the ramus ophthalmicus superficialis. There is 

 accordingly, according to his descriptions, no true ramus 

 ophthalmicus profundus in Acipenser, and there is, moreover, 

 no portio ophthalmici profundi described as such. In hero 

 first giving to the two ophthalmic nerves of Acipenser the 

 names superficialis and profundus, van Wijhe had probably a 

 more direct influence than Balfour on that misapplication of 

 the name profundus that has since been so frequently 

 repeated, and that is so confusing and misleading if one is 

 not continually on one's guard. 



Instances of this misapplication that I am sure of are found 

 in Goronowitsch's descriptions of Acipenser (24), Lota (25), 

 and Salmo (26), and in Wright's descriptions of Amiurus 

 (69) ; and it is exceedingly probable that the same error 

 occurs also in Pollard's descriptions of Siluroids (52). The 

 misapplications relating to Lota and Amiurus have already 

 been recognised and signalled by Herrick and Workmann 

 respectively. 



This use of the term ophthalmicus profundus for a nerve 

 that has the anatomical position of an ophthalmicus super- 

 ficialis always implies, whether intentionally or not, that a 

 nerve having the position of a selachian profundus has moved 

 upward, from that position, to the position of a selachian 



