1868.1 LOVfiN — LESKIA MIR.ABILIS. 441 



fancy I When we remember how minute and concealed the mouth 

 often is in recent Crinoids, we should not be puzzled at its being 

 almost or quite invisible m fossils; and if we should search for 

 the interpretation of an orifice, closed by a definite tow number ot 

 triangular valves, will not several recent Eohimda {EcUnocidaris, 

 EcUnometra «,*«««, Leskia itself,) give us the answer that 

 such an aperture could (at least) be a vent? Nor can I well 

 conceive that an aperture should altogether fad to exis tin the 

 centre of the ambulacral system of Cystidea. How otherwise 

 could the ambulacral vessels communicate with the interior ? 

 And if such an orifice must be assumed (though it be often 

 obliterated and hidden in the fossils), why should not this apical 

 or ambulacral orifice be also the mouth as in Astendse and 

 recent Crinoids, and the valvular orifice be the vent, analogous 

 to the proboscis of the Palaeolithic Crinoids, or the oral tube 

 of the living ?* The superiority of size of the presumed mouth is 

 not as Mr! Billings thinks, a very good argument. Has not 

 the' anal tube in many of our recent Crinoids (Antedcn, Actinome- 

 tra Pmtacrbms) the same preponderance over the minute buccal 

 orifice ? Nor has the repeated revision of the published descrip- 

 tions of other Cystidea, accessible to me, convinced me of the 

 correctness of a theory, according to which the mouth would, in 

 m any instances, lie very far from the arms, sometimes nearer to 

 the base (the stalk or point of attachment) than to the apex of 

 the calyx The argument deduced in later times from the 

 presumed existence of five similar peristomatic valves in the 

 recent Pentacrini, I have elsewhere had the opportunity of 

 refuting ;t no such hard " clapets" are to be seen m P. Mullen 

 and until their existence is proved in other recent Pentacrini I 

 must doubt, or rather deny, their existence at all !| On the other 

 hand I must confess that matters are considerably altered by 

 these' hi-hly valuable investigations of Prof. Loven, who, for the 

 first tinTe, supports this theory with strong (perhaps convincing) 



' The analogy between the valvular aperture of Caryocrinus and the 

 • prohoscS of Crinoids is also argued hy Mr. Billings (Bee. No.3,p. 22). 



, Oni Vestindiens Bentacrinen, p. 205 iVidempel. Meddel. f. d. Natur- 

 hist Porneing, 1864). , 



t Brof Loven told me himself that during his last stay m Bans he 

 succeeded in getting access to the original specimen of Mr. Dachassamg 

 Tthe collection o/the late Mr.Michelin. It did not show the five 

 valves, because it had no peristome at all ! 



