238 Siegfried Becher, 



findet ihn bei P. H. Carpenter (vgl. 1884, p. 50, 51 und 53) und J. Bell 

 (1892). Carpenter bemerkt: „The double or syzygial joints thus 

 formed resemble the ordinary brachials in bearing but one pinnule, 

 and they are therefore best considered as single joints. In Antedon 

 rosacea, for example, the third and fourth, the ninth and tenth, and the 

 fourteenth and fifteenth joints of the growing arm are respectively 

 united in pairs by syzygy ; but the arm is best described as having 

 syzygies in the third, eighth, and twelfth joints" (1884, p. 50). So 

 gründete sich auf das Verhalten der Syzygialglieder und auf die 

 Bezeichnung Syzygium für das ganze Paar eine neue Zählweise für 

 die Armglieder, die bei Carpenter und Bell fast immer, bei 

 J. MtJLLER gelegentlich angewendet wird. Perrier dagegen hielt 

 an der doppelten Zählung der Syzygialpaare fest, was Carpenter's 

 ausgesprochene Mißbilligung erregte (1888, p. 80). 



Dennoch war P. H. Carpenter im Grunde genommen von der 

 ursprünglichen morphologischen Gleichwertigkeit des Hypozygale mit 

 den übrigen Armgliedern überzeugt, das geht aus zahlreichen Sätzen 

 seiner Challenger -Monographie klar hervor. So heißt es unter 

 anderem (1884, p. 50): „The syzygial union of two arm-joints is of 

 a somewhat peculiar character. For 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" . . . und 

 eine Seite weiter: „In Metracrinus nodosus, on the other hand, there 

 are primitively eight radiais, but besides the syzygy between the 

 second and third, there is another between the sixth and seventh- 

 so that there are really only six joints." . . . Schon W. B. Carpenter 

 betont 1866 (p. 734) „that there is no interpolation of new segments 

 (as some have supposed) either at the base or at any part of the 

 length of the arms" . ., das gilt im besonderen auch von dem Hypo- 

 zygale, auch „the syzygies do not originate (as has been supposed 

 by some) in an imperfect subdivision of segment — no subdivision, 

 perfect or imperfect, ever taking place; but that they are formed 

 by a partial coalescence of segments originally quite distinct" 

 (a. a. 0., p. 721). Zur Begiiindung dieser Ansicht führt derselbe 

 Autor am gleichen Orte weiter aus: „P^r in the eaily stage of the 

 existence of this animal as a detached Antedon, there is still so 

 little specialization in the rod-like segments of the arms, that they 

 are all nearly similar in form, have no proper articular surfaces, 

 and are held together by nothing else than an imperfectly fibrous- 

 sarcodic substance" (vgl. auch p. 740). 



