390 p. HERBERT CARPENTER. 



point de doute comme ' des organes des sens ' problematiques." 

 This statement is absolutely untrue. 



There is no mention whatever of the " corps spheriques " of 

 An ted on in the paper to which Perrier refers. But in 

 describing the two kinds of arras of Actinometra armata, 

 namely, those with and those without an ambulacral groove, I 

 said •} " Another difference between these two types of arms is 

 that the curious problematical 'sense organs' which I have 

 mentioned in a former paper are limited to the terminal pin- 

 nules of the non-tentaculiferous arms. The three last seg- 

 ments of these pinnules are very small, but the centre of the 

 dorsal surface of each of the next seven or ten segments is 

 occupied by one of these curious bodies, which when viewed 

 from the exterior appears as a rounded brownish mass," Per- 

 rier, however, has confused these single, median, and antiam- 

 bulacral structures of Actinometra with the double row of 

 sacculi on the ambulacral side of the arms and pinnules in 

 Antedon. 



It is really lamentable that the historical introduction to his 

 elaborate and magnificently illustrated work, which will become 

 a classic ere long, should be disfigured by errors like these. I 

 could name others of the same kind, all of them alike due to 

 sheer carelessness in consulting the works of his predecessors. 

 Speaking of the sacculi on another page (154), Perrier says : 

 " Ces corps enigmatiques ont ete recemment consideres comme 

 des parasites et designes sous le nora de Zooxanthelles. 

 Herbert Carpenter ne trouve pas qu'il y ait encore de raisons 

 suffisantes pour se ranger a cette opinion.^' This statement is 

 supported by no reference whatever to any of my published 

 writings, for the very excellent reason that Professor Perrier 

 has none to give. 



The section on the sacculi in the " Challenger " Report was 

 written in the summer of 1884. This was the last occasion on 

 which I referred to the nature of these structures in print; 

 and it is impossible therefore that 1 could have expressed an 



' " Remarks on tlie Anatomy of the Arms of the Criuoids," Part II, 

 ' Journ. Auat. and Physiol.,' 1876, vol. xi, p. 92. . ■ . . ■ 



