FROGS, TOADS AND SOME FRESH-WATER FISH. 179 



Mongolia and Manchuria. It reaches a weight of 30 Ibs. and upwards, 

 and a length of over three feet. The flesh is very good, and in the Tien- 

 tsin markets it is sold as salmon, for which it, makes a good substitute. 



A trout (Plecoglossus altivelis) is to be found in the streams of 

 the Chin-wang-tao and Shan-hai-kuan districts; but such of the local 

 piscators 1 as have tried the fishing have reported upon it unfavourably. 

 It is the same species that- occurs in Japan. At least two species 

 of trout inhabit the rivers of Eastern and Northern Manchuria, but 

 whether they have been named by scientists I do not know. 



Lastly we have the sturgeon (Acipenser mantschniricus) , which 

 occurs in the Yellow River and sometimes even in the smaller rivers 

 of Chihli. 



The sturgeons, with the sharks are interesting as forming a con- 

 necting link between the fish of the present geological epoch and those 

 of past ages. They have heterocercal or partially forked tails, which 

 is a characteristic of very primitive types of fish. There are no fossil 

 remains of fishes with homocercal or completely forked tails, which is 

 characteristic of the modern fishes such as all of the foregoing species. 



The sturgeon is found also in Manchuria, and in all the rivers of 

 S ; beria and Russia, whence comes that famous delicacy Caviare, which 

 is nothing more nor less than the spawn of this fish. 



