Morphology of the Blastoidea. 297 



of the future who reads Mr. Hambach's papers after a preli- 

 minary study of the works of Johannes Miiller and Alexander 

 Agassiz ? 



Mr. Hambach's discussion* of the affinities of Blastoids, 

 Echinids, and Crinoids commences as follows : — 



" In regard to the relationship of Echinus and Pentremites 

 I would say that it seems quite strange to seek for their 

 nearest allies among the Crinoidege; nevertheless they have 

 been regarded and classified as a suborder to Crinodeas (sic), 

 even Bronn, in his l Klassen und Ordnungen des Thierreichs,' 

 puts them below the Crinoidete, as was done by most of the 

 authors before, and is still clone by others, although Say re- 

 marks already, that ' in a natural series these bodies consti- 

 tute the link between the Crinoideaj and the Echinidre.' " 



He further says that I " certainly cannot point out a Crinoid 

 which bears a stronger resemblance to a Pentremite than a Pen- 

 tremite does to an Echinus." I fully admit that there are many 

 points of resemblance between Pentremites and Echinus, as will 

 be evident from the Appendix to my Eeport on the Crinoidea 

 of the 'Challenger' Expedition f. But like Leuckart, Romer, 

 Huxley, Wyville Thomson, Zittel, Wachsmuth, and many 

 others, I consider the presence or absence of a column as of 

 much greater morphological importance than Mr. Hambach is 

 disposed to attribute to it; and I therefore believe the resem- 

 blance between Pentremites and such a Crinoid as Cupresso- 

 crinus to be far stronger than that between Pentremites and 

 Echinus. Cupressocrinus had a series of minute pinnules 

 along the ambulacra, very closely similar to those of a Blas- 

 toid, and altogether different from the pinnules of an ordinary 

 Crinoid; while there is much reason to think that it was also 

 provided with a hydrospiric apparatus. But these structures 

 \and also the stem), which are so characteristic of a Pentre- 

 mite, are altogether unrepresented in Echinus, and the passage 

 of tentacles through the ambulacral pores of Pentremites is, to 

 put it mildly, an open question. 



Before concluding this communication I should like to 

 correct some errors that unfortunately appeared in the first \ 

 of the two papers on the Blastoids which have been commu- 

 nicated to the l Annals ' by Mr. R. Etheridge, Jun., and my- 

 self. I am bound to admit that they ought never to have 

 found their way into print ; and the only excuse I can offer for 

 their having been published is, that the final revise of our 

 paper was delayed in the post office, and did not reach the 

 printers until the necessity of punctual publication of the 



* Trans. St. Louis Acad. vol. iv. p. 542. 



t Zool. Chall. Exp. part xxxii. p. 413. 



\ ' Annals,' ser. 5, vol. ix. April 1882, pp. 213-252. 



