82 
M. SASAKI. 
consistency of the liver at this season is soft, and the oily content is poor as 
compared with that of the rcddish-hued liver in the spring, which is thick and 
rich. 
Besides the diminution of the oily substance in the liver, all the organs 
generally seem to undergo degeneration, and the vitality of the animals^ is 
considerably lessened. They expired soon even with gentle handling, and 
though they were caught by hand they were very quiet, while in the spring 
time they attacked us violently, biting our hands with their jaws. From the 
middle of July, the catch of Hotaru-ika became gradually less and less, until 
in August and September, a net which had in the sj^ring fishing season caught 
about 500 pounds at a time caught only a very small number. Later it became 
yet smaller, and very feeble animals only were occasionally trawled from the 
depth of 100 or more fathoms. 
By the above facts, we are justified in saying that they probably die with 
the passing of summer. 
5. Female Genital Organ. 
When the mantle of the female caught with the Fiikube-ami was dissected 
along the ventral median line, it was seen that its posterior half is filled up 
with many transparent small eggs of fairly greenish hue. 
Most of the eggs are mature and are freely contained in the ovarial sac, 
which is divided into 2 parts by a median septum. And a comparatively 
small number of immature eggs are imbedded in the ovarial tissue. From 
the central portion of each half of the ovarial sac there arises an oviduct with 
a thin and transparent wall. This oviduct runs backward along its surface 
till near the posterior end of the sac. Then it turns forward, and opens to 
the nidamental gland attached at the anterior end of the sac. In this season 
the oviduct is found to contain a quantity of the fully mature eggs (PI. II, 
fig. 10). 
The nidamental gland is a slightly pinkish body of inverted V-shape 
situated behind the siphon ; each ramus of the gland is split dorso-ventrally 
into 2 lobes with the exception of its posterior 1/6 part. The oviduct arrives 
