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rows, they are densely clustered in the first two-fifths of the body. 
They grow thinner at the beginning of the third fifth of the body 
and soon cease to exist entirely. 
It is significant that they are never 
smaller than the cerebral or the 
tentacular eyes. The cerebral eyes 
(text-fig. 10) are very numerous, 
about 300, and form a much elon- 
gated double cluster with the main 
mass of the eyes anterior to the 
brain. Two separate cerebral eye- 
clusters are distinguishable, although 
they have a tendency to fuse at 
their anterior ends. There is a 
distinet Space between the cerebral 
and the marginal eyes (text-fig. 10). 
Consequently frontal eyes are totally 
absent. The tentacular eye-groups 
are insignificanc — each consists of 
only 5—10 eyes — and lie close 
to the cerebral eye-clusters. A line 
connecting the tentacular rudiments 
would cross the posterior part of 
the brain. A significant feature is 
that the tentacular eyes are actually 
smaller than the cerebral eyes. This 
condition is no doubt due to the 
considerable reduction of the tent- 
acles. A similar tentacular reduction 
is observed in Neostylochus, accom- 
panied by a diminution in the 
number of tentacular eyes. However, 
in the case of Neostylochus their 
size exceeds that of the cerebral eyes. No doubt the tentacles in 
Text-fig. 10. Leptostylochus elongatm 
n. g. n. sp. Cerebial, tentacular, and 
marginal eyes. The brain and the 
circumferences of the slight promin- 
ences representing the tentacular 
rudiments are also drawn. 30 x. 
Limnostylochus have been even more reduced, since neither Stummer- 
Traunfels nor Kaburaki have observed any, However, it is not 
improbable that a sectional examination of Limnostylochus will show 
that they are not entirely absent. In my opinion one must rather 
Vidensk. Medd. fra Dansk naturh. Foren. Bd. 79. 8 
