66 \Y. K. GREGORY. 



movable suspensorium. The first condition is now commonly known as 

 the autostylic, and the second as the hyostylic. 



Comments. This passage is perfectly clear and illuminating. 

 It adheres closely to the essential features of Huxley's concep- 

 tions, and it makes a decided advance beyond them not only in 

 stating clearly that between modern autostyly and hyostyly " no 

 definitely intermediate conditions can be recognized," but also in 

 implicitly reducing the amphistylic mode to its true place as a 

 special phase of the hyostylic a suggestion which has been fol- 

 lowed in the present paper (see above, pp. 57, 59). 



But not even these definitions, I think, will survive. They 

 fail to emphasize the differences between the autostyly of Dipnoi 

 and the autostyly (here termed " holostyly ") of Chimaeroids ; 

 nor do they indicate that by taking also the distal segment of the 

 hyoidean arch into account we may place the whole subject upon 

 a new, and apparently phylogenetic basis. 



In conclusion I desire to thank Professor Henry Fairfield 

 Osborn and especially Professor Bashford Dean for various 

 courtesies and suggestions. 



REFERENCES. 

 Dean, B. 



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Gadow, H. 



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Garman, S. 



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Huxley, T. H. 



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