60 



IIBr2 are reckoned as independent units, and that the first pinnule is 

 on IIBr2. Very well, then the second pinnule is of course on II Br}. 

 Wrong again! it is on IIBr4. In short, words are so juggled with that 

 one must gather everything from the illustrations. 



Now the object of all this confusion seems to be the maintenance 

 of Miiller's statement that »das erste Glied der Arme der Comatulen 

 immer ohne Pinnula ist«, and the retention of »the third brachial as 

 a syzygial [ossicle] as a condition which is common to by far the larger 

 number of Comatulae«. And the difficulty is supposed to be evaded by 

 such an expression as this : »A syzygy between the first two brachials, 

 and another in the third«; in addition to the ineptitude I have ita- 

 licised, the word syzygy here means union, though in the remainder 

 of the very same sentence it means a syzygial pair of ossicles. But all 

 these difficulties would never have occurred had the word syzygy al- 

 ways been used in its original sense as defined by Müller, and had 

 the primitive brachials always been reckoned as the morphological 

 units which they are. The formulae of Bell or of Carpenter could 

 have been constructed just as well by basing them on joints (i. e. uni- 

 ons) and not on ossicles. 



3) The reform proposed. — I have no wish to upset things and 

 so make confusion worse confounded ; but I do ask the describers of 

 crinoids to settle the meaning of the terms they employ. And Avhen 

 they are settling these matters it would be as well if they extended 

 their observations beyond the limits of three or four genera of recent 

 crinoids and considered the difficulties presented by other forms. The 

 evidence of palaeontology shows that a syzygy is a specialised form of 

 joint, gradually acquired, and more common in the later than in the 

 earlier crinoids. Moreover, such extreme specialisation of arrange- 

 ment as enables our systematists to construct their beautifully com- 

 prehensive formulae, is found only in the Antedonidae. Consequently 

 in the earlier crinoids one often comes upon cases in which a syzygial 

 union seems to have existed without much modification of the size 

 of the ossicles. In many of these cases, as Carpenter admits, it is 

 ridiculous to reckon two brachials as one element even though they 

 be united by syzygy. In other cases, in Bathycrinus for instance, as 

 Carpenter points out, there is a modification of ossicles and an ab- 

 sence of pinnules without true syzj'gy. The argument of expediency, 

 though not particularly scientific, has its weight when we consider 

 that the difficulty, experienced by the highest authorities, of deter- 

 mining from external appearances whether certain unions are syzygial 

 or not, must result, on Carpenter's system, in a corresponding un- 

 certainty as to the actual number of the ossicles. In fine, to make the 



