136 
Muller’s specimens had the point of the postero-lateral arms red 
coloured (and, judging from his figure, quite conspicuously so), and 
the young star also had a big red patch in the middle of the 
dorsal side; the specimens observed by me had only a faint yel- 
lowish tint in the end of the arms and in the middle of the dorsal 
side of the young star, the larva being otherwise milky white 
and opaque, so that the skeleton could not be seen distinctly 
without applying some clearing fluid. This diversity in colour 
being the only notable difference between the two larvæ it seems 
justifiable to regard them as identical or, at least, as belonging to 
two very closely related species. The faet that there were no dis¬ 
tinet ciliated bands along the postero-lateral arms, together with 
the peculiar opaqueness of the larva, would seem to indicate that 
this larva does not have the full pluteus shape, but belongs to 
the rudimentary larval forms. This cannot, however, be decided, 
before larvæ have been observed in which the metamorphosis is 
less advanced than in those observed till now. 
The occurrence of this larval form both in the Adriatic and at the 
coast of Bohuslån allows a suggestion about the Ophiuroid to which 
it must belong. The following Ophiuroids are common to the Scan- 
dinavian seas and the Adriatic: Opliiura texturata, O. cilbida , O. 
af/in is, Amphiura filiformis, A. Chiajei , Amphipholis squamata , 
Ophiothrix fragilis and probably also Ophiocoma nigra. Of these 
species one, Amph. squamata , is viviparous and thus cannot come 
into consideration. The larvæ of Ophiura texturata, O. atbida, Am¬ 
phiura fdiformis (see below) and Ophiothrix fragilis are known, 
these species being thus also eliminated; likewise Ophiocoma ni¬ 
gra, evidently, is out of question. 1 ) Amphiura Chiajei and Ophiura 
affinis thus alone can come into consideration as species to which 
this larva could belong. Joh. Muller, in faet, suggested that the 
larva might possibly belong to Amphiura Chiajei (he names it 
incorrectly Ophiolepis Sundevatti; as it is especially noticed that 
the species has two tentacle scales, it is beyond doubt that the 
species meant is Amph. Chiajei ), his reason for this suggestion 
being that the dorsal side of the disk in this species is red as in 
’) Th. Mortensen. On the development of some British Echinoderms. 
Journ. Mar. Biol. Assoc. N. Ser. X. 1913. p. 12. 
