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union — and this is the original definition and the universally accepted 

 meaning of the term — then it is inconsistent with the meaning 

 to reckon syzygies in the above-mentioned manner : the imits must be 

 unions or joints , and not ossicles. For instance one would say of 

 Antedon rosacea »the third, ninth, and fourteenth joints are syzygies«; 

 and such a mode of expression would be short, simple, intelligible, 

 and consistent. 



Usage, however, counts for much ; so I have tried to find out how 

 the usage arose, and how far it is carried out. Here again there is 

 confusion , the usual consequence of a confused terminology. In his 

 memoir »Über den Bau des Pentacrmusa ^ on p. 217, Müller reckons 

 each brachial as an independent unit, saying »An der inneren Seite 

 eines Armes ist es immer das dritte Glied, welches die erste Pin nula 

 trägt, oder das Glied über den beiden Syzygialgliedern.« It is when 

 one comes to tabulate the arrangement of the pinnules that the point 

 of counting a syzygial pair as one ossicle becomes apparent; for, as 

 Müller says (op. cit. p. 218), »beim Alternieren der Pinnulae die 

 beiden Glieder, die ein Syzygium bilden, immer nur für ein Glied 

 zählen, daß das Hypozygale ohne Pin nula ist und daß die Pin- 

 nula jedes Mal am Epizygale steht«. In the words of P. H. Car- 

 penter (Challenger Report on Stalked Crinoids, p. 50), »the hypozygal 

 entirely loses its individuality as a separate segment of the arm, and 

 bears no pinnule as the epizygal and the remaining brachials do — 

 The double or syzygial [ossicles] thus formed resemble the ordinary 

 brachials in bearing but one pinnule, and they are therefore best 

 considered as single [ossicles]«. So obvious is this to Carpenter that, 

 on p. 80 of his Challenger Report on the Comatulae, he hurls scorn 

 and sarcasm at Prof. Perrier, who has followed the simpler method 

 of reckoning the hypozygal and epizygal as two brachials. 



So then Müller and P. H. Carpenter, not to mention other 

 writers, reckon a syzygial pair as a single ossicle. Oh! no, nothing of 

 the sort : Only when it pleases them to do so, and when it fits in with 

 their general statements. Look at Carpenter's description ai Acti- 

 nometî'a pedinata for example (Challenger Report; Comatulae p. 285), 

 — »The first pair of pinnules (on second and third brachials) . ..« What 

 does this mean ? In this species the brachials that I should call II Bri aud 2 

 and IIHr3and4, are respectively united by syzygial suture; therefore 

 one supposes that, in accordance with Carpenter's system, they 

 are reckoned as two brachials; and one infers that the first pinnule, 

 which is said to be on the second brachial, must be borne by IIBr4, 

 since that is the epizygal of the second syzygial pair. But this inference 

 postulates too great consistency; one soon discovers that II Bri and 



