464 Notices of Memoirs— Dr. R. H. Traquair's Address. 



condition. But though we cannot expect that the palasontological 

 record will ever be anj^thing more than fragmentary, yet the constant 

 occurrence of new and important discoveries leads us to entertain 

 the hope that, in course of time, more and more of its pages will 

 become disclosed to us. 



Incomplete, however, as our knowledge of Evolution as derived 

 from Paleontology must be, that is no reason why we should not 

 appraise it at its proper value, and now and again stop for a moment 

 to take stock of the material which has accumulated. 



You are all already acquainted with the telling evidence in favour 

 of Evolution furnished by the well-known series of Mammalian 

 limbs, as well as of teeth, in which the progress, in the course of 

 time, from the more general to the more special is so obvious that 

 I cannot conceive of any unprejudiced person shutting his eyes to 

 the inference that Descent with modification is the reason of these 

 things being so. Suppose, then, that on this occasion we take up 

 the palasontological evidence of Descent in the case of fishes. This 

 I do the more readily because what original work I have been able 

 to do has lain principally in the direction of fossil ichthyology ; and 

 again, because it does seem to me that it is in this department that 

 one has most reason to complain of want of interest on the part of 

 recent biologists, even, I may say, of some professed paleeontologists 

 themselves. I shall in the main limit myself to the consideration of 

 Palaeozoic forms. 



Here I may begin by boldly affirming that I include the Marsipo- 

 branchii as fishes, in spite of the dictum of Cope that no animal can 

 be a fish which does not possess a lower jaw and a shoulder-girdle. 

 Why not ? The position seems to me to be a merely arbitrary one ; 

 and it is, to say the least, not impossible that the modern Lampreys 

 and Hags may be, as many believe, the degenerate descendants of 

 originally gnathostomatous forms. 



To the origin of the Vertebrata Palaeontology gives us no clue, as 

 the forerunners of the fishes must have been creatures which, like 

 the lowest Chordata of the present day (Tunicata, Balanoglossus, 

 Amphioxiis), had no hard parts capable of preservation. And though 

 I shall presently refer again to the subject, I may here affirm that, 

 so far as I can read the record at least, it is impossible to derive from 

 Palaeontology any support to the view, recently revived, that the 

 ancient fishes are in any way related to Crustacean or merostomatous 

 ancestors. 



What have we, then, to say concerning the most ancient fishes 

 with which we are acquainted ? 



The idea that the minute bodies known as Conodonts, which occur 

 from the Cambrian to the Carboniferous, are the teeth of fishes and 

 possibly even of ancient Marsipobranchs may now be said to be 

 given up. They are now accepted by the most reliable authorities 

 as appertaining to Invertebrata such as Annelides and Gephyrea. 



More recently, however, Eohon ^ has described from the Lower 



^ " Ueber untersiluiisclie Fische " : Melanges Geol. et Paleont., vol. i 

 (St. Petersburg, 1899), pp. 9-14. 



