Echinological Notes. 
By 
Dr. Th. Mortensen • 
V. The Phylogeny of the Echini. A critieal essay. 
Piofessor R. T. Jack s on, the author of the “Phylogeny of 
the Echini”, has expressed the desire of seeing his work >) reviewed 
by me. With pieasuie I take the task upon me. Though the 
echinological literature has, especially in recent times, received many 
veiy important contnbutions, this work represents a rather uniqne 
ennchment of this branch of science, equally remarkable through 
lts magmficent appearance and its high scientific value. To review 
such a monumental work is in itself both a pleasure and a honour 
Meantime Prof. H. L. Clark has published in “Science”, 
June 28. 1912, an elaborate review in which he gives a rather 
detailed summary of the contents and the more prominent results 
the work. I must join Professor Clark sincerely in his deep 
appreciation of the work and in his admiration for the eminent 
skill and unsurpassed industry and perseverance of the author; but 
the appearance of his review makes it superfluous for me to give 
likewise a summary of the contents of the work, whieh could not 
avoid being essentially a repetition of what H. L. Clark has already 
said. Probably also Prof. Jacks on will prefer, instead of receiving 
another eulogy in similar terms from my band, to have a criticism 
') Robert Tracy Jackson: Phylogeny of the Echini, with a Revision 
° r, al r°‘ C specles - Mem - Boston Soc. Nat. Hist. Vol. 7 , 1912 
(With 76 Plates). ’ 
14 * 
