Bd. VI: 8) 
THE CRINOIDEA. 
7 
limit for the presence of the genital organs; they are just gradually diminishing in 
size towards the 12th — 14th joint, and may continue as rudiments beyond that point. 
The eggs must break through the wall separating the ovary from the marsupium. 
Whether a definite opening exists, I cannot ascertain definitely. The figure PI. IV, 3 
would seem to prove that such a preformed opening does exist; but I have seen it 
only in this one case. The eggs are not very large, only ca. 0.2—3 mm. Quite a 
number of ripe or nearly ripe eggs are found at the same time in the ovary (PI- IV, 
Figs. 2 — 4); but there is generally only one or two embryos in each marsupium, 
rarely three (PI. Ill, Fig. 2). These facts would seem to indicate that some of the 
eggs do not develop, but are dissolved and possibly serve as nourishment for the 
embryos. I have in some cases found a yellow, coarsely granulated substance in 
marsupia, without embryos, which had decidedly the appearance of being eggs in 
disintegration. This would also seem to corroborate the supposition that some of 
the eggs are destined to serve as nourishment for the developing embryos. But 
I cannot ascertain this as a definitely established fact. 
The embryos are found to be all at very nearly the same stage of development; 
this would seem to indicate that the eggs are emptied into the marsupia not at any 
time, but a larger number at the same time, as is also the case in other Crinoids 
with free eggs, thus far observed. On account of this fact it was impossible to study 
the whole of the embryonal development, only two stages being represented. Also 
the postembryonal development remains unknown, no Pentacrinoids having been found. 
It may be allowed to suggest that the Pentacrinoids remain attached to the genital 
pinnules, as is the case in Thcnnnatometva nutrix (see below, p. 17). For this sug- 
gestion is speaking the fact that the embryos have no trace of vibratile bands and 
thus must be incapable of swimming. But in the absence of any observations re- 
garding the later stages of development, this can be nothing but a mere suggestion. 
An account of the structure of the embryos will be given in the memoir on 
Crinoid development mentioned in the Introduction. It should only be mentioned 
here that they are considerably larger than the embryos of any other Crinoid, as far 
as known, being nearly 2 mm. in length. 
In PI. IV, Fig. I is seen a small, elongate body lying in the cavity of the ovary. 
This is a parasitic organism. Having been unable to find any other specimen of this 
parasite, I do not venture to state definitely, what it is. It is nearest to suggest that 
it is a Myzostomid — but this cannot be ascertained. In any case, it seems well 
worth while pointing out the existence of a true internal parasite in this Crinoid. 
It is easily enough seen that this highly interesting Crinoid represents a new 
genus. More difficult is the question about the affinities of that genus. 
Some of its structural features, evidently, are of a primitive character, e. g. the 
