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more inclined to regard the Adriatic form as a distinet species, 
though, of course, closely related to O. af/inis. If this view be 
correct, the interest connected with this larva would be greatly 
augmented. We would then here have the first case of the larvæ 
of two closely related species of the genus Ophiura being closely 
alike, in conformity with what should be expected from the analogy 
of other Echinoderm larvæ, and the great diversity of e. g. the 
larvæ of Ophiura texturata and albida would then be a proof 
that these Ophiuroids are not really so closely related as hitherto 
generally supposed, not a proof against the value of the larval 
characters as tests for the systematic relations of the adult. — 
Further researches on this wide-bearing problem must be expected 
with the greatest interest. 
II. Amphiura filiformis (O. F. Muller). 
The most common of all the Ophiuroid-larvæ occurring at the 
Zoological Station of Kristineberg, at least from the later part of 
July until the middle of September, is the form described by 
me in „Nordisches Plankton“ under the name of Ophiopluteus 
mancus. Considering its occurrence in so large numbers it was 
evident that it must belong to a species of Ophiurid correspondingly 
abundant in the neighbourhood of the Station. Eliminating those 
species of which the larvæ were known already, there were hardly 
any other species to which it could be referred than the two spec¬ 
ies of Amphiura , A. filiformis and Chiajei. No larva being known 
hitherto which could with any reasonable degree of probability be 
referred to Amphiura , I was, of course, very anxious to get de- 
finite proof of the origin of this larva. Two ways might give the 
desired result, viz. rearing the larvæ from the egg or rearing the 
young Ophiurid from the larva till a State sufficiently advanced to 
recognize it as an Amphiura. During the summer of 1918 all 
efforts to get the Amphiura’s to shed their eggs in the aquaria 
proved in vain, and artificial fertilization did not succeed either, 
as upon the whole it is next to impossible to get Ophiurid-eggs 
fertilized, when taken out of an opened female, in the way used 
with so splendid success in almost all Echinoids, very generally in 
Asteroids and in many cases also in Holothurians. The other way, 
