314 DR. U. H. TEAQTJAIR ON PAL^'EOSPONDTLUS GUNNi/ [Mar. 16, 



thought to represeut fin-rays, were not organic and had nothing 

 whatever to do with the fish. Similar ridges were to he seen on 

 a specimen with Pala'ospomhjlus in the Museum of Practical 

 Geology, but had no relation to the fossil. 



The following papers were read : — 



1. Note on the Affinities of PalcROspondylus gunni, Traq. 

 In reply to Dr. Bashford Dean, of New York. By 

 R. H. Tkaquair, M.D., LL.D., F.R.S.' 



[Eeceived March 16, 1897.] 



Those who are acquainted with my papers on Palceospondnlus 

 gunni will remember that my principal reason, in my last contri- 

 bution to the subject, for assigning a Marsipobi'anch affinity to this 

 singular little Devonian organism was the presence of a cirrated 

 opening, presumably nasal, situated in the front of the cranium. 

 My words were : — 



" What is the nature of this aperture with its strange fringe 

 of cirri ? It cannot be a sucker like that of the larval Lepidosteus. 



The more obvious comparison — and that which is in 



harmouy with the rest of the structure of our fossil — is that with 

 the single nasal opening of Myxine or Petromyzon. And if this 

 view be the right one, then Palaospomhjlus is monorhinal, and is 

 a Marsipobranch." ^ 



I was therefore not a little surprised to find the following 

 statement by Dr. Bashford Dean at p. 70 of his recent work on 

 ' Fishes Living and Fossil,' published after he had received and 

 read the paper from which the above extract is quoted : — " There 

 can be no doubt that Palceospondylus possessed a ring-like mouth 

 surrounded by barbels like those of a Myxinoid, and that it lacked 

 paired fins." 



Not that Dr. Dean seems to dispute my reference of the cirrated 

 opening to a nasal category — on the contrary he reproduces my 

 restoration of PalceospondylKS without raising any question of the 

 kind. So I can only conclude that he did not read my description 

 with that amount of care which would have prevented so serious 

 a misunderstanding of ray words, which surely could not have 

 been plainer. 



In this woi-k, however, the author looks favourably on the idea 

 of the Marsipobranch affinities of Pala'ospondylus, even to the 

 extent of speaking of it as " the fossil remains of what seems 

 undoubtedly a Lamprey " (p. 65). 



More recently, however. Dr. Dean has seen reason to change 

 this opinion after examining a specimen of Palceospondylus which 



^ Commnnicated by A. Smith Woodward, Esq., F.Z.S. 

 * Proc. Koy. Pbys." Soc. Ediiib. vol. xii. 1894, p. 314. 



