NOTES ON ECHINODERM MORPHOLOGY. 155 
between the ovoid gland and the oral blood-vascular ring only 
sugggest the possibility of an even closer resemblance between 
the vascular systems of Urchins and Starfishes than has hitherto 
been thought possible. 
Will he not complete his work, and give a convincing 
demonstration of the truth of his own statements, so as to 
disprove the views of those morphologists, like myself, who 
believe in the fundamental distinctness of the two vascular 
systems throughout the Stellerids, Crinoids, and Urchins? 
Postscript.—Two more notes upon Crinoid Anatomy have 
been published by Professor Perrier! since I last wrote upon 
the subject in the pages of this Journal.? The second one, 
which has only appeared quite recently, closes as follows :— 
“‘ Chez les Comatules comme chez les Oursins, ce qu’on a appelé 
Vappareil vasculaire est en communication avec le systéme des 
canaux ambulacraires.” 
As regards the Urchins, the nature of the evidence on which 
Professor Perrier relies has been explained above, while I have 
discussed his statements about the Crinoids in my report upon 
the “ Challenger’ Crinoida.* When his illustrated memoir 
upon the Anatomy of Comatula has appeared, I intend to go 
into the whole question again, and I will only say at present 
that I have seen no evidence of a communication between 
water-vascular and blood-vascular systems in any of the five 
genera of Crinoids which I have examined, while neither Greeff, 
Teuscher, nor Ludwig make any mention of it. At the same 
time I am bound to confess that I never thought of looking 
for it at all until its existence was asserted by Professor 
Perrier, and I shall await his demonstration of it with very 
great interest. 
1 Anatomie des Echinodermes ; sur l’organisation des Comatules adultes,’’ 
‘Comptes rendus,’ tom. xcvili, No. 23, June 9th, 1884, pp. 1448—1450; and 
Sur le développement de l’appareil vasculaire, et de l’appareil genital des 
Comatules,” ibid., tom. c, 16th February, 1885. 
2 «Notes on Hchinoderm Morphology,” No. 3, “On Some Points in the 
Anatomy of Larval Comatule,” ‘Quart. Journ. Micr. Sci.,’ vol. xxiv, 1884, 
pp. 8319—327. 
3 «Zool. Chall. Exp.,’ part xxxii, pp. 106, 40— 407. 
