il THE VOYAGE OF H.M.S. CHALLENGER. 
and the earlier months of the following year, the greater part of which time was spent 
at Wiirzburg, where I had the constant advantage of Prof. Semper’s criticism and 
advice. I also received much valuable help from my father, who freely placed at my 
disposal all the material which he had accumulated some years before for his mvestigation 
of the structure of Antedon, Pentacrinus, and Rhizocrinus. A portion of his observations 
were communicated to the Royal Society in his now classical memoir on the skeleton of 
Antedon rosacea, and in a later paper on the anatomy of the disk and arms. but he has 
still a large amount of unpublished material; and of this I have always been permitted to 
avail myself as fully -} I wished. How important this help has been to me will be 
vppareit to every subs quent worker at Crinoid morphology, my own researches having 
followed very closely on \the lines which he had laid down. The results of my study of 
Aetinomeira aud various other Crinoids were communicated to the Linnean Society in the 
sumumer of 1877, and shortly afterwards Sir Wyville Thomson offered to entrust me with 
the preparation of the Report upon the Comatule dredged by the Challenger. The 
collection was sent to me in January 1878; and for the next four years the time which I 
could spare from my professional duties was devoted pretty continuously to the examina- 
tion and description of some hundred and fifty new species. Eighteen plates had been 
drawn and nearly all the specific diagnoses written out, when on Sir Wyville’s untimely 
death in March 1882 I was requested by Mr. John Murray to include the Stalked 
Crinoids in my Report. 
During the cruise of H.M.S. Challenger, and also for some years before it, Sir 
Wyville had devoted much attention to the Stalked Crinoids, and he proposed himself 
to investigate the collection of this group of animals which was made during the Expedi- 
tion. He also arranged with Prof. Alexander Agassiz that he should embody the 
descriptions of the Stalked Crinoids dredged in the Caribbean Sea by the U.S. Coast 
Survey steamer “ Blake” in his Report on the Challenger collection, so that it might 
assume the form of a monograph of all the species known to science. He was able 
to do but little with the “‘ Blake” collection, however; and with the concurrence of Prof. 
Agassiz it was sent to me by Mr. Murray along with the Challenger collection, proofs 
of plates, drawings, preparations, and some notes, in the spring of 1882. 
Sir Wyville had not made much progress with the preparation of his Report. Twenty- 
eight plates illustrating the structure of Holopus and of the more remarkable types 
dredged by the Challenger had been drawn and lithographed at Edinburgh under his 
superintendence by Messrs. George West and W. 8. Black, but he was never able to 
draw up any specific diagnoses; and he left no manuscript behind him of any kind, 
except one or two generic and specific names which he had written upon the proofs of 
some of these plates. Descriptions of Hyocrinus, Bathycrinus, and of Pentacrinus 
maclearanus had, however, already been published in his popular work on the Voyage of 
the Challenger—The Atlantic. 
