290 Dr. P. H. Carpenter on the 



am sorry to have to give Mr. Hamback so much trouble ; but 

 as in a previous case [ante, p. 285) , I really must ask him where 

 I have made the statement which he paraphrases. It is cer- 

 tainly not in my account of the genus Troostocrinus on 

 pp. 247-249 of the ' Annals ' for April 1882, of which he 

 has a copy. I have never spoken of Troostocrinus cla- 

 vatus. I did say, however, that tl the most important 

 morphological difference between Troostocrinus and Pentremites 

 lies in the structure of the spiracles." But this is very diffe- 

 rent from Mr. Hambach's account of my views, which is 

 hopelessly inaccurate, and not supported by any reference 

 whatever to my published papers. Many of Mr. Hambach's 

 observations are more accurate than those of his predecessors. 

 It is unfortunate that he cannot carry on a discussion with 

 the same care as he evidently bestows on the examination of 

 his Pentremites. 



His assertion that all described Pentremites outside Codaster 

 and Orophocrinus (Codonites, Hambach) "can easily be dis- 

 tributed" in one or other of the three divisions which he 

 defines, is a somewhat comprehensive generalization. It 

 could only be made with any approach to accuracy by an 

 observer who had personally examined " all described Pen- 

 tremites" or, at any rate, had provided himself with accu- 

 rate descriptions and figures of those which were inaccessible 

 to him. One is therefore naturally led to inquire how far 

 Mr. Hambach's generalization is applicable to some of the 

 European Blastoids which have been described under the 

 general name Pentremites : for example — (1) Pentremites in- 

 Jiatus, Sow , P. pentangular is, Bronn, P. Water housianus, 

 De Koninck, P. Orbignyanus, De Kon., and P. puzos, 

 Minister ; (2) Pentremites acutus, Phillips, and P. caryophyl- 

 Jatus, De Kon. Not one of these is mentioned by Mr. Ham- 

 bach at all, nor do their characters in any way accord with 

 either of his descriptions of the three divisions into which he 

 groups the species of Pentremites. The first five of them 

 have been referred by Mr. Etheridge and myself* to Oropho- 

 crinus or Codonites, as Mr. Hambach prefers to call it; and 

 it may be that he accepts this identification, though he no- 

 where alludes to it. But even if this be the case there remain 

 the two species Pentremites acutus and P. caryophyllatus, for 

 which there is absolutely no place in Mr. Hambach's classi- 

 fication. They are excluded from his third division by having 

 imperforate deltoid pieces ; from the second division, which 

 have broad deltoid pieces, and ten distinctly visible spira- 

 * ' Annals/ ser. 5, vol. i-x. p. 252. 



