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better than that obtained in the aquaria; not one larva had attached 
itself, but some of the still surviving larvæ had at least the skel- 
eton much more developed than ever found in the aquaria, though 
still not quite normal. Although the experiment thus proved a fail- 
ure, I have little doubt that it must be possible to obtain a good 
result in this way; probably a much larger size of the cage would 
be needed. That conditions within the cage were not quite un- 
natural appears from the faet that the Bryozoa and Hydroids con- 
tained in it were found to be in a flourishing condition. 
While I was thus unable to get the metamorphosis stages, a 
fairly complete material of the postlarval stages was obtained. The 
Pentacrinoids were found attached especially to Hydroids, but also 
to Bryozoa, worm tubes and other objects from the localities where 
the adult Antedons abound. It was a rather troublesome work 
to examine carefully the material from the dredgings, under fairly 
high power in order not to overlook the important younger stages; 
but a fairly good series of Pentacrinoids of different stages was 
the result. It is not the place here to give a detailed description 
of the Pentacrinoids. It should only be emphasized that a careful 
study of the younger stages revealed the faet that Infrabasalia 
are present in this species. On dissol ving the calyx of young 
Pentacrinoids by means of hypochlorite of sodium under the micro- 
scope it is seen that there are 3 small, equal-sized infrabasalia, 
forming a small ring which lies wholly inside the basalia, so that 
it is impossible to observe it on intact specimens. This faet led 
me to the wrong statement (Echinoderms of North East Greenland, 
p. 251) that infrabasalia are not found in this species. The devel- 
opment of the anal plate and the adjoining radial is in full accord- 
ance with the observations regarding this point I have made on 
other Crinoids, as described in the memoir referred to above. The 
conclusions arrived at there with regard to the question of the 
alleged homology between the anal plate of Comatulids and the 
radianal of older Crinoids are thus fully born out by the observ¬ 
ations on the Pentacrinoids of the present species also. 
Regarding the development and transformation of the inner 
organs I cannot give a satisfactory account. This species proves to 
be a most unfavourable object, especially because of the small 
size of the histological elements and the unusually small content 
