Alleged Cases of Misrepresentation. 485 



larva homologous with plate x of the Fistulata, and interradial 

 in position." 



I am willing to admit that their present statement is quite 

 consistent with Part III. of the Revision, and had they chosen 

 to say as much in that work I should not have been led astray 

 by the following considerations. 



In their paper on Hybocrinus, Hoplocrinus and Baero- 

 crinus, p. 377, they said u the 'anal' plate of the young 

 Antedon is evidently not the homologue of the plate in the 

 Cyathocrinida3 which we have designated as the ' special ' 

 anal plate, but .... it is the equivalent of the undivided 

 azygous plate in Baerocrinus and Hoplocrinus.'''' On this 

 they subsequently remarked [Revision III. (p. 196), footnote ; 

 Proc. 1886, p. 120] " In making this statement we had over- 

 looked the fact that the latter plate* is simply an interradial 

 with special function, while the azygous plate in Baero- 

 crinus is as much radial as interradial." If they had meant 

 what now they say they meant, they should have taken this 

 opportunity of stating that they then considered the anal 

 plate of Antedon to be homologous with the special anal of 

 the Cyathocrinida3. That certainly was not what I inferred 

 from the above- quoted footnote : for, I argued, if the azygos 

 of Baerocrinus is as much radial as interradial, so also is the 

 special anal plate that was once a part of it ; but the anal of 

 Antedon is simply an interradial, therefore it cannot be homo- 

 logous with the special anal of the Cyathocrinidae. 



In an earlier part of Revision III. (p. 39) published in 1885 

 (Proc. p. 261) they had laid some emphasis on the distinction 

 between " interradials " and " the one true anal plate," and, 

 although it is quite true that they compared the various 

 positions assumed during growth by the anal of Antedon with 

 the positions occupied in the evolutionary series by the anal 

 plate of the Fistulata, still they never definitely stated the 

 homology. 



Even the sentence which they now (p. 390) quote from 

 Rev. III. p. 40, that " at last in Cyathocrinus the latter plate 

 [Azygos] was entirely removed, and the anal plate took the 

 position of that in the larva of Antedon" does not necessarily 

 imply homology ; had they said " the anal plate took the 

 position that it occupies in the larva of Antedon" this would 

 have shown that they considered the two plates homologous. 

 I, reading the sentence in the light of their subsequent foot- 

 note, naturally supposed that the ambiguity of its wording 

 was intentional. 



* Anal of Antedon larva. 

 Ann. cfc Mag. N. Hist. Ser. 6, Vol. vii. 33 



