Bd. VI: 8) THE CRINOIDEA. 9 



logical grounds, not very probable, and I do not see the proof of it in the figures of 

 sections given by Cakpentek. The main point to prove it, in fact, seems to be the 

 absence of pigmentation in these basal rays — and this is, certainly, not a feature of 

 sufficient importance to prove the remarkable tertiary« character of these rays. It 

 would also be a verj- unusual feature, in case these rays were really a structure 

 morphologically and histologically so different from the basais, that they unite so 

 completely with the basais, that it is quite impossible to separate them. It should 

 be expected both that the structural character of the calcareous tissue of the rays, if 

 really developed among the straight fibres of the synostosis, would be quite different 

 from that of the basalia and other plates, and also that a line of union between the 

 rays and the basais could be made out. But nothing of the kind is observed. 



Upon the whole the definite proof of the tertiarj- character of the basal rays 

 could hardly be found in their histological character alone. The study of their deve- 

 lopment alone would give that. Until it has been proved in this way that the basal 

 rays have the morphological value ascribed to them by CARPENTER I must regard 

 them as an integral part of the basais; their different size in the various Comatulids 

 just marks different stages in the transformation of the basalia. 



We may now proceed to discuss the question to which family of the Comatulids 

 Notoci-iuiis must be referred. 



It is at once evident that it cannot belong to the Oligophreatœ. It is decidedly 

 of the macrophreate tj'pe. Of the three families of the ^lacrophreata, Atelecrinida;, 

 Antedonidœ and Pentametrocrinidae, the latter is at once excluded. The presence of 

 basalia recall the Atelccri)iidie, in which famih- similar small basalia occur in Atopo- 

 crinus (regarded by A. H. CLARK as -basal rays« ; Monograph of the existing Crinoids, 

 p. 245). The peculiar character of the cirrus sockets, so characteristic of the Atele- 

 crinidic, however, does not occur in Xotocrinus and it cannot, accordingly, be referred 

 to that family either. Thus the family AntedonidiC alone remains. The arrangement 

 in columns of the cirrus sockets agrees with the subfamily Zenoinctriim: but other- 

 wise the characters of the, centrodorsal, the central pore and the large basal groove 

 does not correspond with this family; also the short, stout oral pinnules, the plating 

 of the disk and the retension of the basais and the anal plate are characters not 

 normally met with in the Antedonidie. Finally, the unique character of the genital 

 organs seems to preclude the idea that Xotocrinus could be referred to the Ante- 

 donidœ any more than to any of the other families of Comatulids — and that it is 

 not a special adaptation to the viviparous habit of this form is evident from the fact 

 that also the males have their genital organs placed in the arms, not in the pinnules. 

 The only logical course then seems to establish a separate family for this peculiar 

 Crinoid. 



2 — 173534. Schwedische Siidpolar-Expedition iqoi — igoj. 



