MEMOIRS. 
The Minute Anatomy of the BRacHIATE ECHINODERMS. 
By P. Hersert Carpenter, M.A., Assistant- Master 
at Eton College. With Plates XI and XII. 
In the following pages I propose to give some account of 
the work that has been done during the last few years upon 
the minute anatomy of the Starfishes, Ophiurids, and 
Crinoids. I do not intend to touch upon the question of 
the skeleton at all, as I have already discussed its mor- 
phology in the pages of this Journal. At present I aim 
only at giving an intelligible account of what appear to be 
well-established discoveries in the anatomy and physiclogy 
of the nervous, vascular, and generative systems of these 
three groups. 
By far the most important of the recent researches in this 
subject are those of Ludwig.? Others may have devoted 
more attention to particular groups, but no one has worked 
so extensively at increasing our general store of facts in 
Echinoderm morphology as he has; while, at the same time, 
his observations are by far the most accurate and trustworthy 
of any that have been recorded. Although there are one 
or two theoretical points with respect to which our opinions 
are entirely different, I have no hesitation in saying that I 
have the utmost confidence in his facts. There are, of 
course, many anatomical peculiarities that were more or less 
perfectly elucidated by his predecessors, but on the whole, 
no one has done so much as he has towards correlating, 
systematising, and verifying or correcting the more or less 
conflicting observations of other investigators. 
} “The Oral and Apical Systems of the Echinoderms,” ‘Quart. Journ. 
Micr. Sci.,’ vols. xviii and xix. ‘‘Some disputed points in Echinoderm 
Morphology,” ‘Quart. Journ. Mier. Sci.,’ vol. xx. 
* Morphologische Studien an Echinodermen,” Leipzig, 1877—79. 
These were originally published as separate papers in the ‘ Zeitschrift fur 
Wissenschaftliche Zoologie,’ Bande xxviii, seqq. 
VOL, XXI.——NEW SER. M 
