390 PROCEEDINGS OF THE ACADEMY OF [1890. 



A careful examination of both sections of Pt. Ill of the Revision, 

 will show nothing to justify Bather in assuming that we regarded 

 the Azygos as a " primitive element." We only stated on p. 11 : 

 " the lower segments (of the compound radials) are probably embr)'-- 

 onic plates, which were resorbed by the upper segments." We ad- 

 mit that the expression ''resorbed by " was badly chosen, we should 

 have stated : were resorbed and occupied by the upper segments, but 

 that is not the issue here. 



Bather's second statement is equally inaccurate. If he had said 

 that we regarded the anal plate (X) and right posterior radial as 

 derived from the undivided Azygos in Baerocrinus, he would have ex- 

 pressed our views. 



His third statement is more faulty yet. To agree with Pt. Ill of 

 the Revision it should be amended as follows : Anal plate oi Ante- 

 don larva homologous with plate X of the Fistulata, and interradial 

 in position. At that time we thought it even possible, and said so on 

 pp. 39 and 40, that the anal plate of Antedon was developed from 

 an " Azygos plate," and that : " Possibly the undivided Azygos plate, 

 as represented in Baerocrinus, has been overlooked in the larva." 

 We stated further on the same page " that at least in Cyathocrinus 

 the latter (Azygos) plate was entirely removed, and the anal plate 

 took the position of that in the larva of Antedon," thus showing con- 

 clusively that we regarded the two plates as structurally identical. 



Another incorrect statement we find on p. 323. There Bather 

 asserts that we stated " the ' anal' oi Antedon\n.YWix is an interradial 

 with special function, while the Azygos plate is as much radial as 

 interradial." The fact is we said the Azygos plate " in Baerocrinus,^^ 

 and not the Azygos generally, is as much radial as interradial. In a 

 supplementary note to his paper, in the June number of the Annals, 

 on p. 486, he alludes to this omission, stating that he left out the 

 words purposely, " since they (we) in the very next sentence imply 

 that Baerocrinus is an ancestral stage," and " that a simple and exact 

 quotation would have tended to confuse the issues." This is taking 

 altogether too great liberty with the text. We stated correctly 

 that the " Azygos of Baerocrinus is neither radial nor interradial," 

 for it rests between two radials and alternates with the basals ; but 

 to say the same thing of Homocrinus, Dendrocrinus, etc. would be 

 ridiculous. 



