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 CARPENTER. 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 very 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 tertiary 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 
Notocrinus must be referred. 
It is at once evident that it cannot belong to the Oligophreatæ. It is decidedly 
of the macrophreate type. Of the three families of the Macrophreata, Atelecrinidæ, 
Antedonidæ and Pentametrocrinidæ, the latter is at once excluded. The presence of 
basalia recall the Atelecrinidæ , in which family 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- 
crinidæ ^ however, does not occur in Notocrinus and it cannot, accordingly, be referred 
to that family either. Thus the family Antedonidæ alone remains. The arrangement 
in columns of the cirrus sockets agrees with the subfamily Zenometrinæ ; 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 Antedonidæ. Finally, the unique character of the genital 
organs seems to preclude the idea that Notocrinus could be referred to the Ante- 
donidæ 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 Südpolar-Expediiion iqoi — içoj. 
