Instincts, Habits, and Adaptations 45 
little fishes (Gobiomorus, Carangus, Psenes) cluster under the 
stinging tentacles of the Portuguese man-of-war or under 
ordinary jellyfishes. In the tide-pools, whether rock, coral, 
or mud, in all regions multitudes of little fishes abound. As 
these localities are neglected by most collectors, they have 
proved of late years a most prolific source of new species. 
Fie, 31.—Pearl-fish, Fierasfer acus (Linneus), issuing from a Holothurian. 
Coast of Italy. (After Emery.) 
The tide-pools of Cuba, Key West, Cape Flattery, Sitka, Una- 
laska, Monterey, San Diego, Mazatlan, Hilo, Kailua and Waiane 
in Hawaii, Apia and Pago-Pago in Samoa, the present ~ 
writer has found peculiarly rich in rock-loving forms. Even 
richer are the pools of the promontories of Japan, Hakodate. 
Head, Misaki, Awa, Izu, Waka, and Kagoshima, where a whole 
new fish fauna unknown to collectors in markets and sandy 
bays has been brought to light. Some of these rock-fishes are 
left buried in the rock weeds as the tide flows, lying quietly 
until it returns. Others cling to the rocks by ventral suckers, 
while still others depend for their safety on their powers of 
leaping or on their quickness of their movements in the water. 
Those of the latter class are often brilliantly colored, but the 
others mimic closely the algee or the rocks. Some fishes live in 
the sea only, some prefer brackish water. Some are found only 
