360 AXNTAL REPORT SMITHSONIAN INSTITUTION, 1953 



wei-e related to our far-off ancestors, the Rhipidistia, but they "were 

 never in the direct line of evolution and repi-esent a sort of biological 

 backwater. 



As to the claim that they may throAv light on our remote ancestry, 

 this can be said: since the first coelacanths were related to the an- 

 cestral line, and since they have changed so little in outward form, 

 they may have preserved some of the primitive features common to 

 them both. But whether they will in fact tell us so very much more 

 than we have already learned from the other surviving gi'oup of 

 fringe-tinned fishes, the lungfishes, renuiins to be seen. In any case, 

 whetlier it proves to be primitive or otherwise the internal anatomy 

 of these curious fishes is certain to be of great interest to the specialist. 

 The nuitter of the ossified air sac has already been noted, although 

 disappointingly there is no mention of such an organ in the prelimi- 

 nary accounts, which lay emphasis on the possession of a spiral valve 

 in the intestine. The latter character is less remarkable than the 

 absence of the spiral valve would have been, as it commonly occurs 

 in the moi-e primitive living fishes. But there are plenty of other 

 details we should like to know about them, and Professor Smith's 

 detailed report will be awaited with the keenest interest by zoologists 

 throughout the world. 



Reprints of the various articles in this Report may be obtained, as long as 

 the supply lasts, on request to the Editorial and Publications Division, 

 Smithsonian Institution, Washington 25, D. C. 



