ON THREE INTERESTING NEW OEGOTSIDS FROM THE BAY OF SAGAMI. 137 
posterior regions, it seems to be composed of about twenty organs, as occurs 
in M. hoylci. 
The lateral regions of the dorsal surface of the head are provided with 
organs much smaller and mucli thinner in distribution than those of the vent- 
ral surface. The arrangement is irregular and asymmetrical on both sides, 
the organs of the right side being more numerous than those of the left side. 
When the head is seen laterally, the size and distribution of the organs differ 
greatly between the right and left sides : on the right side, the organs are 
numerous, becoming rarer towards the dorsal side, and there is found a longi- 
tudinal zone entirely free from organs, crossing the eye-opening and extend- 
ing from the angle between the third and fourth arms to the neck. The mar- 
gin of the eye-opening of this side is provided with twenty-four organs around 
the whole edge. The left side of the head has very few and minute organs, 
which are entirely lacking around the margin of the eye-opening. 
The series of the luminous organs of the arms are only the continuation 
of those of the head, being arranged in some longitudinal series. The outer 
surface of the right ventral arm is thickly covered with the organs. There 
are nine series of the organs at the extreme base, which become reduced to 
six in the middle and to one at the extremity, the series which reaches to the 
extremity being the second one among the nine series from the ventral side. 
On the proximal part of the third pair of arms, there are two series of the 
luminous organs which are all situated in a more ventral jDosition than the 
median tubercular series, and the longest one of the two, comprising about 
forty organs, reaches the extreme end of the arm. The dorsal side of the 
median tubercular series has only a few organs of small size. 
The ventral side of the tubercular series on the second pair of arms is 
provided also with two series of the luminous organs at the proximal part. 
The longer series of the two, comprising about thirty-three organs, reaches 
the extremities of the arms. The organs on the dorsal side of the tubercular 
series show nearly the same character in distribution as those on the equal 
surface of the third pair, but much less frequently. The organs of the first 
