Instincts, Habits, and Adaptations 159 



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. 



FIG. 121. Pearl-fish, Fierasfer acus (Linnaeus), 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 Waiahae 

 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 algae or the rocks. Some fishes live in 

 the sea only, some prefer brackish water. Some are found only 



